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Disponibile in 34 lingue" > <label id="p-lang-btn-label" for="p-lang-btn-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--action-progressive mw-portlet-lang-heading-34" aria-hidden="true" ><span class="vector-icon mw-ui-icon-language-progressive mw-ui-icon-wikimedia-language-progressive"></span> <span class="vector-dropdown-label-text">34 lingue</span> </label> <div class="vector-dropdown-content"> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li class="interlanguage-link interwiki-ar mw-list-item"><a href="https://ar.wikipedia.org/wiki/231_(%D8%B9%D8%AF%D8%AF)" title="231 (عدد) - arabo" lang="ar" hreflang="ar" data-title="231 (عدد)" data-language-autonym="العربية" data-language-local-name="arabo" class="interlanguage-link-target"><span>العربية</span></a></li><li class="interlanguage-link interwiki-az mw-list-item"><a href="https://az.wikipedia.org/wiki/231_(%C9%99d%C9%99d)" title="231 (ədəd) - azerbaigiano" lang="az" hreflang="az" data-title="231 (ədəd)" data-language-autonym="Azərbaycanca" data-language-local-name="azerbaigiano" class="interlanguage-link-target"><span>Azərbaycanca</span></a></li><li class="interlanguage-link interwiki-azb mw-list-item"><a href="https://azb.wikipedia.org/wiki/%DB%B2%DB%B3%DB%B1_(%D8%B3%D8%A7%DB%8C%DB%8C)" title="۲۳۱ (سایی) - South Azerbaijani" lang="azb" hreflang="azb" data-title="۲۳۱ (سایی)" data-language-autonym="تۆرکجه" data-language-local-name="South Azerbaijani" class="interlanguage-link-target"><span>تۆرکجه</span></a></li><li class="interlanguage-link interwiki-bg mw-list-item"><a href="https://bg.wikipedia.org/wiki/231_(%D1%87%D0%B8%D1%81%D0%BB%D0%BE)" title="231 (число) - bulgaro" lang="bg" hreflang="bg" data-title="231 (число)" data-language-autonym="Български" data-language-local-name="bulgaro" class="interlanguage-link-target"><span>Български</span></a></li><li class="interlanguage-link interwiki-cdo mw-list-item"><a href="https://cdo.wikipedia.org/wiki/231" title="231 - Mindong" lang="cdo" hreflang="cdo" data-title="231" data-language-autonym="閩東語 / Mìng-dĕ̤ng-ngṳ̄" data-language-local-name="Mindong" class="interlanguage-link-target"><span>閩東語 / Mìng-dĕ̤ng-ngṳ̄</span></a></li><li class="interlanguage-link interwiki-ckb mw-list-item"><a href="https://ckb.wikipedia.org/wiki/%D9%A2%D9%A3%D9%A1_(%DA%98%D9%85%D8%A7%D8%B1%DB%95)" title="٢٣١ (ژمارە) - curdo centrale" lang="ckb" hreflang="ckb" data-title="٢٣١ (ژمارە)" data-language-autonym="کوردی" data-language-local-name="curdo centrale" class="interlanguage-link-target"><span>کوردی</span></a></li><li class="interlanguage-link interwiki-cs mw-list-item"><a href="https://cs.wikipedia.org/wiki/231_(%C4%8D%C3%ADslo)" title="231 (číslo) - ceco" lang="cs" hreflang="cs" data-title="231 (číslo)" data-language-autonym="Čeština" data-language-local-name="ceco" class="interlanguage-link-target"><span>Čeština</span></a></li><li class="interlanguage-link interwiki-eml mw-list-item"><a href="https://eml.wikipedia.org/wiki/231_(n%C3%B9mer)" title="231 (nùmer) - Emiliano-Romagnolo" lang="egl" hreflang="egl" data-title="231 (nùmer)" data-language-autonym="Emiliàn e rumagnòl" data-language-local-name="Emiliano-Romagnolo" class="interlanguage-link-target"><span>Emiliàn e rumagnòl</span></a></li><li class="interlanguage-link interwiki-en mw-list-item"><a href="https://en.wikipedia.org/wiki/231_(number)" title="231 (number) - inglese" lang="en" hreflang="en" data-title="231 (number)" data-language-autonym="English" data-language-local-name="inglese" class="interlanguage-link-target"><span>English</span></a></li><li class="interlanguage-link interwiki-eu mw-list-item"><a href="https://eu.wikipedia.org/wiki/Berrehun_eta_hogeita_hamaika" title="Berrehun eta hogeita hamaika - basco" lang="eu" hreflang="eu" data-title="Berrehun eta hogeita hamaika" data-language-autonym="Euskara" data-language-local-name="basco" class="interlanguage-link-target"><span>Euskara</span></a></li><li class="interlanguage-link interwiki-fa mw-list-item"><a href="https://fa.wikipedia.org/wiki/%DB%B2%DB%B3%DB%B1_(%D8%B9%D8%AF%D8%AF)" title="۲۳۱ (عدد) - persiano" lang="fa" hreflang="fa" data-title="۲۳۱ (عدد)" data-language-autonym="فارسی" data-language-local-name="persiano" class="interlanguage-link-target"><span>فارسی</span></a></li><li class="interlanguage-link interwiki-fr mw-list-item"><a href="https://fr.wikipedia.org/wiki/231_(nombre)" title="231 (nombre) - francese" lang="fr" hreflang="fr" data-title="231 (nombre)" data-language-autonym="Français" data-language-local-name="francese" class="interlanguage-link-target"><span>Français</span></a></li><li class="interlanguage-link interwiki-ga mw-list-item"><a href="https://ga.wikipedia.org/wiki/231_(uimhir)" title="231 (uimhir) - irlandese" lang="ga" hreflang="ga" data-title="231 (uimhir)" data-language-autonym="Gaeilge" data-language-local-name="irlandese" class="interlanguage-link-target"><span>Gaeilge</span></a></li><li class="interlanguage-link interwiki-ht mw-list-item"><a href="https://ht.wikipedia.org/wiki/231_(nonm)" title="231 (nonm) - creolo haitiano" lang="ht" hreflang="ht" data-title="231 (nonm)" data-language-autonym="Kreyòl ayisyen" data-language-local-name="creolo haitiano" class="interlanguage-link-target"><span>Kreyòl ayisyen</span></a></li><li class="interlanguage-link interwiki-hu mw-list-item"><a href="https://hu.wikipedia.org/wiki/231_(sz%C3%A1m)" title="231 (szám) - ungherese" lang="hu" hreflang="hu" data-title="231 (szám)" data-language-autonym="Magyar" data-language-local-name="ungherese" class="interlanguage-link-target"><span>Magyar</span></a></li><li class="interlanguage-link interwiki-ja mw-list-item"><a href="https://ja.wikipedia.org/wiki/231" title="231 - giapponese" lang="ja" hreflang="ja" data-title="231" data-language-autonym="日本語" data-language-local-name="giapponese" class="interlanguage-link-target"><span>日本語</span></a></li><li class="interlanguage-link interwiki-ko mw-list-item"><a href="https://ko.wikipedia.org/wiki/231" title="231 - coreano" lang="ko" hreflang="ko" data-title="231" data-language-autonym="한국어" data-language-local-name="coreano" class="interlanguage-link-target"><span>한국어</span></a></li><li class="interlanguage-link interwiki-mk mw-list-item"><a href="https://mk.wikipedia.org/wiki/231_(%D0%B1%D1%80%D0%BE%D1%98)" title="231 (број) - macedone" lang="mk" hreflang="mk" data-title="231 (број)" data-language-autonym="Македонски" data-language-local-name="macedone" class="interlanguage-link-target"><span>Македонски</span></a></li><li class="interlanguage-link interwiki-mni mw-list-item"><a href="https://mni.wikipedia.org/wiki/%EA%AF%B2%EA%AF%B3%EA%AF%B1" title="꯲꯳꯱ - manipuri" lang="mni" hreflang="mni" data-title="꯲꯳꯱" data-language-autonym="ꯃꯤꯇꯩ ꯂꯣꯟ" data-language-local-name="manipuri" class="interlanguage-link-target"><span>ꯃꯤꯇꯩ ꯂꯣꯟ</span></a></li><li class="interlanguage-link interwiki-ms mw-list-item"><a href="https://ms.wikipedia.org/wiki/231_(nombor)" title="231 (nombor) - malese" lang="ms" hreflang="ms" data-title="231 (nombor)" data-language-autonym="Bahasa Melayu" data-language-local-name="malese" class="interlanguage-link-target"><span>Bahasa Melayu</span></a></li><li class="interlanguage-link interwiki-mzn mw-list-item"><a href="https://mzn.wikipedia.org/wiki/%DB%B2%DB%B3%DB%B1_(%D8%B9%D8%AF%D8%AF)" title="۲۳۱ (عدد) - mazandarani" lang="mzn" hreflang="mzn" data-title="۲۳۱ (عدد)" data-language-autonym="مازِرونی" data-language-local-name="mazandarani" class="interlanguage-link-target"><span>مازِرونی</span></a></li><li class="interlanguage-link interwiki-nso mw-list-item"><a href="https://nso.wikipedia.org/wiki/231_(nomoro)" title="231 (nomoro) - sotho del nord" lang="nso" hreflang="nso" data-title="231 (nomoro)" data-language-autonym="Sesotho sa Leboa" data-language-local-name="sotho del nord" class="interlanguage-link-target"><span>Sesotho sa Leboa</span></a></li><li class="interlanguage-link interwiki-ps mw-list-item"><a href="https://ps.wikipedia.org/wiki/%DB%B2%DB%B3%DB%B1_(%D8%B9%D8%AF%D8%AF)" title="۲۳۱ (عدد) - pashto" lang="ps" hreflang="ps" data-title="۲۳۱ (عدد)" data-language-autonym="پښتو" data-language-local-name="pashto" class="interlanguage-link-target"><span>پښتو</span></a></li><li class="interlanguage-link interwiki-ro mw-list-item"><a href="https://ro.wikipedia.org/wiki/231_(num%C4%83r)" title="231 (număr) - rumeno" lang="ro" hreflang="ro" data-title="231 (număr)" data-language-autonym="Română" data-language-local-name="rumeno" class="interlanguage-link-target"><span>Română</span></a></li><li class="interlanguage-link interwiki-sv mw-list-item"><a href="https://sv.wikipedia.org/wiki/231_(tal)" title="231 (tal) - svedese" lang="sv" hreflang="sv" data-title="231 (tal)" data-language-autonym="Svenska" data-language-local-name="svedese" class="interlanguage-link-target"><span>Svenska</span></a></li><li class="interlanguage-link interwiki-sw mw-list-item"><a href="https://sw.wikipedia.org/wiki/Mia_mbili_thelathini_na_moja" title="Mia mbili thelathini na moja - swahili" lang="sw" hreflang="sw" data-title="Mia mbili thelathini na moja" data-language-autonym="Kiswahili" data-language-local-name="swahili" class="interlanguage-link-target"><span>Kiswahili</span></a></li><li class="interlanguage-link interwiki-tt mw-list-item"><a href="https://tt.wikipedia.org/wiki/231_(%D1%81%D0%B0%D0%BD)" title="231 (сан) - tataro" lang="tt" hreflang="tt" data-title="231 (сан)" data-language-autonym="Татарча / tatarça" data-language-local-name="tataro" class="interlanguage-link-target"><span>Татарча / tatarça</span></a></li><li class="interlanguage-link interwiki-uk mw-list-item"><a href="https://uk.wikipedia.org/wiki/231_(%D1%87%D0%B8%D1%81%D0%BB%D0%BE)" title="231 (число) - ucraino" lang="uk" hreflang="uk" data-title="231 (число)" data-language-autonym="Українська" data-language-local-name="ucraino" class="interlanguage-link-target"><span>Українська</span></a></li><li class="interlanguage-link interwiki-ur mw-list-item"><a href="https://ur.wikipedia.org/wiki/231_(%D8%B9%D8%AF%D8%AF)" title="231 (عدد) - urdu" lang="ur" hreflang="ur" data-title="231 (عدد)" data-language-autonym="اردو" data-language-local-name="urdu" class="interlanguage-link-target"><span>اردو</span></a></li><li class="interlanguage-link interwiki-uz mw-list-item"><a href="https://uz.wikipedia.org/wiki/231_(son)" title="231 (son) - uzbeco" lang="uz" hreflang="uz" data-title="231 (son)" data-language-autonym="Oʻzbekcha / ўзбекча" data-language-local-name="uzbeco" class="interlanguage-link-target"><span>Oʻzbekcha / ўзбекча</span></a></li><li class="interlanguage-link interwiki-vi mw-list-item"><a href="https://vi.wikipedia.org/wiki/231_(s%E1%BB%91)" title="231 (số) - vietnamita" lang="vi" hreflang="vi" data-title="231 (số)" data-language-autonym="Tiếng Việt" data-language-local-name="vietnamita" class="interlanguage-link-target"><span>Tiếng Việt</span></a></li><li class="interlanguage-link interwiki-zh mw-list-item"><a href="https://zh.wikipedia.org/wiki/231" title="231 - cinese" lang="zh" hreflang="zh" data-title="231" data-language-autonym="中文" data-language-local-name="cinese" class="interlanguage-link-target"><span>中文</span></a></li><li class="interlanguage-link interwiki-zh-min-nan mw-list-item"><a href="https://zh-min-nan.wikipedia.org/wiki/231" title="231 - min nan" lang="nan" hreflang="nan" data-title="231" data-language-autonym="閩南語 / Bân-lâm-gú" data-language-local-name="min nan" class="interlanguage-link-target"><span>閩南語 / Bân-lâm-gú</span></a></li><li class="interlanguage-link interwiki-zh-yue mw-list-item"><a href="https://zh-yue.wikipedia.org/wiki/231" title="231 - cantonese" lang="yue" hreflang="yue" data-title="231" data-language-autonym="粵語" data-language-local-name="cantonese" class="interlanguage-link-target"><span>粵語</span></a></li> </ul> <div class="after-portlet after-portlet-lang"><span class="wb-langlinks-edit wb-langlinks-link"><a href="https://www.wikidata.org/wiki/Special:EntityPage/Q379154#sitelinks-wikipedia" title="Modifica collegamenti interlinguistici" class="wbc-editpage">Modifica collegamenti</a></span></div> </div> </div> </div> </header> <div class="vector-page-toolbar"> <div class="vector-page-toolbar-container"> <div id="left-navigation"> <nav aria-label="Namespace"> <div id="p-associated-pages" class="vector-menu vector-menu-tabs mw-portlet mw-portlet-associated-pages" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="ca-nstab-main" class="selected vector-tab-noicon mw-list-item"><a href="/wiki/231_(numero)" title="Vedi la voce [c]" accesskey="c"><span>Voce</span></a></li><li id="ca-talk" class="new vector-tab-noicon mw-list-item"><a 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decoding="async" width="18" height="18" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/b/bc/Nota_disambigua.svg/27px-Nota_disambigua.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/b/bc/Nota_disambigua.svg/36px-Nota_disambigua.svg.png 2x" data-file-width="200" data-file-height="200" /></span></span> <span class="hatnote-text"><a href="/wiki/Aiuto:Disambiguazione" title="Aiuto:Disambiguazione">Disambiguazione</a> – "Duecentotrentuno" rimanda qui. Se stai cercando altri significati, vedi <b><a href="/wiki/231_(disambigua)" class="mw-disambig" title="231 (disambigua)">231 (disambigua)</a></b>.</span></div> </div> <style data-mw-deduplicate="TemplateStyles:r143074810">.mw-parser-output .sinottico{background-color:#f8f9fa;border:1px solid #c8ccd1;border-spacing:0;clear:right;float:right;font-size:95%;line-height:1.4em;margin:0 0 1em 1.5em;width:280px}.mw-parser-output .sinottico caption{font-weight:bold}.mw-parser-output .sinottico>tbody>tr>th:not(:only-child),.mw-parser-output .sinottico_annidata>tbody>tr>th:not(:only-child){background-color:#f3f3f3;border-right:1px solid #e5e5e8;text-align:left;vertical-align:top}.mw-parser-output .sinottico>tbody>tr:not(:last-child)>td,.mw-parser-output .sinottico>tbody>tr:not(:last-child)>th,.mw-parser-output .sinottico_annidata>tbody>tr>td,.mw-parser-output .sinottico_annidata>tbody>tr>th{border-bottom:1px solid #e0e0e0}.mw-parser-output .sinottico>tbody>tr>td,.mw-parser-output .sinottico>tbody>tr>th:not(:only-child),.mw-parser-output .sinottico_annidata>tbody>tr>td,.mw-parser-output .sinottico_annidata>tbody>tr>th:not(:only-child){padding:.25em .4em}.mw-parser-output .sinottico>tbody>tr>td,.mw-parser-output .sinottico_annidata>tbody>tr>td{vertical-align:middle}.mw-parser-output .sinottico>tbody>tr>td>hr:only-child{margin:0.4em 0.2em}.mw-parser-output .sinottico ul{margin:0 0 0 1em;padding:0}.mw-parser-output .sinottico_annidata{border-spacing:0;margin:0 -.4em;width:calc(100% + calc(.4em*2))}.mw-parser-output .sinottico_annidata:last-child{margin-bottom:-.2em}.mw-parser-output .sinottico_annidata:last-child>tbody>tr:last-child>td,.mw-parser-output .sinottico_annidata:last-child>tbody>tr:last-child>th{border-bottom:none}.mw-parser-output .sinottico_divisione+.sinottico_divisione>th,.mw-parser-output .sinottico_testata+.sinottico_divisione>th{border-top:2px solid #f8f9fa}.mw-parser-output .sinottico_divisione th{background-color:#eeeeee;padding:.15em .4em;text-align:center}.mw-parser-output .sinottico_piede{text-align:center;font-size:90%;background:#EFEFEF}.mw-parser-output .sinottico_piede2{background-color:white;font-size:xx-small;padding-bottom:0;text-align:right}.mw-parser-output .sinottico_sottotitolo{font-size:80%}.mw-parser-output .sinottico_testata th{background-color:#dedede;font-size:116%;padding:.2em .4em;text-align:center}.mw-parser-output .sinottico_testo_centrale{text-align:center}</style><table class="infobox sinottico" summary="Tabella sinottica che riassume i principali dati del soggetto"><tbody><tr class="sinottico_testata"><th colspan="2" style="background:#C0C0FF">231</th></tr><tr><th><a href="/wiki/Numero_cardinale" title="Numero cardinale">Cardinale</a></th><td>Duecentotrentuno </td></tr><tr><th><a href="/wiki/Numero_ordinale" title="Numero ordinale">Ordinale</a></th><td>Duecentotrentunesimo, -a </td></tr><tr><th><a href="/wiki/Fattorizzazione" title="Fattorizzazione">Fattori</a></th><td>3 × 7 × 11 </td></tr><tr><th><a href="/wiki/Sistema_di_numerazione_romano" title="Sistema di numerazione romano">Numero romano</a></th><td>CCXXXI </td></tr><tr><th><a href="/wiki/Sistema_numerico_binario" title="Sistema numerico binario">Numero binario</a></th><td>11100111 </td></tr><tr><th><a href="/wiki/Sistema_numerico_esadecimale" title="Sistema numerico esadecimale">Numero esadecimale</a></th><td>E7 </td></tr><tr class="sinottico_divisione"><th colspan="2" style="background:#D2D2FF">Valori di funzioni aritmetiche</th></tr><tr><td class="sinottico_testo_centrale" colspan="2">  <table style="width:100%;"> <tbody><tr> <td><a href="/wiki/Funzione_%CF%86_di_Eulero" title="Funzione φ di Eulero">φ(231)</a> = 120 </td> <td><a href="/wiki/Funzione_tau_sui_positivi" title="Funzione tau sui positivi">τ(231)</a> = 8 </td> <td><a href="/wiki/Funzione_sigma" title="Funzione sigma">σ(231)</a> = 50 </td></tr> <tr> <td><a href="/wiki/Funzione_enumerativa_dei_primi" title="Funzione enumerativa dei primi">π(231)</a> = 8 </td> <td><a href="/wiki/Funzione_di_M%C3%B6bius" title="Funzione di Möbius">μ(231)</a> = -1 </td> <td><a href="/wiki/Funzione_di_Mertens" title="Funzione di Mertens"><i>M</i>(231)</a> = 0 </td></tr></tbody></table> </td></tr></tbody></table> <p><b>Duecentotrentuno</b> (231) è il <a href="/wiki/Numero_naturale" title="Numero naturale">numero naturale</a> dopo il <a href="/wiki/230_(numero)" title="230 (numero)">230</a> e prima del <a href="/wiki/232_(numero)" title="232 (numero)">232</a>. </p> <meta property="mw:PageProp/toc" /> <div class="mw-heading mw-heading2"><h2 id="Proprietà_matematiche"><span id="Propriet.C3.A0_matematiche"></span>Proprietà matematiche</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=231_(numero)&veaction=edit&section=1" title="Modifica la sezione Proprietà matematiche" class="mw-editsection-visualeditor"><span>modifica</span></a><span class="mw-editsection-divider"> | </span><a href="/w/index.php?title=231_(numero)&action=edit&section=1" title="Edit section's source code: Proprietà matematiche"><span>modifica wikitesto</span></a><span class="mw-editsection-bracket">]</span></span></div> <ul><li>È un <a href="/wiki/Numero_dispari" class="mw-redirect" title="Numero dispari">numero dispari</a>.</li> <li>È un <a href="/wiki/Numero_composto" title="Numero composto">numero composto</a> con otto <a href="/wiki/Divisore" title="Divisore">divisori</a>: 1, 3, 7, 11, 21, 33, 77 e 231. Poiché la somma dei suoi divisori è <a href="/wiki/153_(numero)" title="153 (numero)">153</a> < 230, è un <a href="/wiki/Numero_difettivo" title="Numero difettivo">numero difettivo</a>.</li> <li>È il ventiduesimo <a href="/wiki/Numero_sfenico" title="Numero sfenico">numero sfenico</a>, ovvero prodotto di tre <a href="/wiki/Fattori_primi" class="mw-redirect" title="Fattori primi">fattori primi</a> distinti.</li> <li>È il ventunesimo <a href="/wiki/Numero_triangolare" title="Numero triangolare">numero triangolare</a>, la somma dei primi 21 numeri interi. Anche <a href="/wiki/21_(numero)" title="21 (numero)">21</a> è un numero triangolare, il sesto; e anche <a href="/wiki/6_(numero)" title="6 (numero)">6</a> è un numero triangolare. È quindi il triangolo di un triangolo di un triangolo.</li> <li>È inoltre un <a href="/wiki/Numero_esagonale" title="Numero esagonale">numero esagonale</a>, <a href="/wiki/Numero_poligonale" title="Numero poligonale">17-gonale</a>, <a href="/wiki/Numero_poligonale" title="Numero poligonale">78-gonale</a> e <a href="/wiki/Numero_poligonale_centrato" title="Numero poligonale centrato">23-gonale centrato</a>.</li> <li>È un <a href="/wiki/Numero_ottaedrico" title="Numero ottaedrico">numero ottaedrico</a>.</li> <li>È un <a href="/wiki/Successione_di_Thue-Morse" title="Successione di Thue-Morse">numero malvagio</a>.</li> <li>È il numero delle <a href="/wiki/Partizione_di_un_intero" title="Partizione di un intero">partizioni</a> di <a href="/wiki/16_(numero)" title="16 (numero)">16</a>.</li> <li>Può essere espresso in quattro modi diversi come differenza di due <a href="/wiki/Numero_quadrato" class="mw-redirect" title="Numero quadrato">quadrati</a>: 231=16<sup>2</sup>-5<sup>2</sup>=20<sup>2</sup>-13<sup>2</sup>=40<sup>2</sup>-37<sup>2</sup>=126<sup>2</sup>-115<sup>2</sup>.</li> <li>È un <a href="/wiki/Numero_palindromo" title="Numero palindromo">numero palindromo</a> in <a href="/wiki/Base_2" class="mw-redirect" title="Base 2">base 2</a> (11100111) e nel <a href="/wiki/Sistema_di_numerazione_posizionale" title="Sistema di numerazione posizionale">sistema di numerazione posizionale</a> a <a href="/wiki/Base_20" class="mw-redirect" title="Base 20">base 20</a> (BB) e a <a href="/w/index.php?title=Base_32&action=edit&redlink=1" class="new" title="Base 32 (la pagina non esiste)">base 32</a> (77). In queste due ultime base è altresì un <a href="/wiki/Numero_a_cifra_ripetuta" title="Numero a cifra ripetuta">numero a cifra ripetuta</a>.</li> <li>È parte delle <a href="/wiki/Terne_pitagoriche" class="mw-redirect" title="Terne pitagoriche">terne pitagoriche</a> (108, 231, 255), (160, 231, 281), (231, 308, 385), (231, 392, 455), (231, 520, 569), (231, 792, 825), (231, 1260, 1281), (231, 2420, 2431), (231, 2960, 2969), (231, 3808, 3815), (231, 8892, 8895), (231, 26680, 26681).</li> <li>È un <a href="/wiki/Numero_fortunato" title="Numero fortunato">numero fortunato</a>.</li> <li>È un <a href="/wiki/Numero_congruente" title="Numero congruente">numero congruente</a>.</li></ul> <div class="mw-heading mw-heading2"><h2 id="Astronomia">Astronomia</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=231_(numero)&veaction=edit&section=2" title="Modifica la sezione Astronomia" class="mw-editsection-visualeditor"><span>modifica</span></a><span class="mw-editsection-divider"> | </span><a href="/w/index.php?title=231_(numero)&action=edit&section=2" title="Edit section's source code: Astronomia"><span>modifica wikitesto</span></a><span class="mw-editsection-bracket">]</span></span></div> <ul><li><a href="/wiki/231P/LINEAR-NEAT" title="231P/LINEAR-NEAT">231P/LINEAR-NEAT</a> è una <a href="/wiki/Cometa_periodica" title="Cometa periodica">cometa periodica</a> del <a href="/wiki/Sistema_solare" title="Sistema solare">sistema solare</a>.</li> <li><a href="/wiki/231_Vindobona" title="231 Vindobona">231 Vindobona</a> è un <a href="/wiki/Asteroide" title="Asteroide">asteroide</a> della <a href="/wiki/Fascia_principale" title="Fascia principale">fascia principale</a> del sistema solare.</li></ul> <div class="mw-heading mw-heading2"><h2 id="Astronautica">Astronautica</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=231_(numero)&veaction=edit&section=3" title="Modifica la sezione Astronautica" class="mw-editsection-visualeditor"><span>modifica</span></a><span class="mw-editsection-divider"> | </span><a href="/w/index.php?title=231_(numero)&action=edit&section=3" title="Edit section's source code: Astronautica"><span>modifica wikitesto</span></a><span class="mw-editsection-bracket">]</span></span></div> <ul><li>Cosmos 231 è un <a href="/wiki/Satellite_artificiale" title="Satellite artificiale">satellite artificiale</a> <a href="/wiki/Russia" title="Russia">russo</a>.</li></ul> <div class="mw-heading mw-heading2"><h2 id="Altri_ambiti">Altri ambiti</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=231_(numero)&veaction=edit&section=4" title="Modifica la sezione Altri ambiti" class="mw-editsection-visualeditor"><span>modifica</span></a><span class="mw-editsection-divider"> | </span><a href="/w/index.php?title=231_(numero)&action=edit&section=4" title="Edit section's source code: Altri ambiti"><span>modifica wikitesto</span></a><span class="mw-editsection-bracket">]</span></span></div> <ul><li>+231 è il <a href="/wiki/Prefisso_telefonico_internazionale" class="mw-redirect" title="Prefisso telefonico internazionale">prefisso telefonico internazionale</a> della <a href="/wiki/Liberia" title="Liberia">Liberia</a>.</li> <li>Nel <a href="/wiki/Sistema_consuetudinario_statunitense" title="Sistema consuetudinario statunitense">sistema consuetudinario statunitense</a>, è il numero di <a href="/wiki/Pollice_(unit%C3%A0_di_misura)" title="Pollice (unità di misura)">pollici</a> cubi contenuti in un <a href="/wiki/Gallone" title="Gallone">gallone</a>.</li> <li>È il numero delle possibili combinazioni di due delle 22 <a href="/wiki/Lettera_(alfabeto)" class="mw-redirect" title="Lettera (alfabeto)">lettere</a> dell'<a href="/wiki/Alfabeto_ebraico" title="Alfabeto ebraico">alfabeto ebraico</a>, da cui i "231 cancelli" del <a href="/wiki/Sefer_Yetzirah" title="Sefer Yetzirah">Sefer Yetzirah</a>.</li></ul> <div class="mw-heading mw-heading2"><h2 id="Altri_progetti">Altri progetti</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=231_(numero)&veaction=edit&section=5" title="Modifica la sezione Altri progetti" class="mw-editsection-visualeditor"><span>modifica</span></a><span class="mw-editsection-divider"> | </span><a href="/w/index.php?title=231_(numero)&action=edit&section=5" title="Edit section's source code: Altri progetti"><span>modifica wikitesto</span></a><span class="mw-editsection-bracket">]</span></span></div> <div id="interProject" class="toccolours" style="display: none; clear: both; margin-top: 2em"><p id="sisterProjects" style="background-color: #efefef; color: black; font-weight: bold; margin: 0"><span>Altri progetti</span></p><ul title="Collegamenti verso gli altri progetti Wikimedia"> <li class="" title=""><span class="plainlinks" title="commons:Category:231 (number)"><a class="external text" href="https://commons.wikimedia.org/wiki/Category:231_(number)?uselang=it">Wikimedia Commons</a></span></li></ul></div> <ul><li><span typeof="mw:File"><a href="https://commons.wikimedia.org/wiki/?uselang=it" title="Collabora a Wikimedia Commons"><img alt="Collabora a Wikimedia Commons" src="//upload.wikimedia.org/wikipedia/commons/thumb/4/4a/Commons-logo.svg/18px-Commons-logo.svg.png" decoding="async" width="18" height="24" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/4/4a/Commons-logo.svg/27px-Commons-logo.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/4/4a/Commons-logo.svg/36px-Commons-logo.svg.png 2x" data-file-width="1024" data-file-height="1376" /></a></span> <span class="plainlinks"><a class="external text" href="https://commons.wikimedia.org/wiki/?uselang=it">Wikimedia Commons</a></span> contiene immagini o altri file su <b><span class="plainlinks"><a class="external text" href="https://commons.wikimedia.org/wiki/Category:231_(number)?uselang=it">231</a></span></b></li></ul> <div class="noprint" style="width:100%; padding: 3px 0; display: flex; flex-wrap: wrap; row-gap: 4px; column-gap: 8px; box-sizing: border-box;"><div style="flex-grow: 1"><style data-mw-deduplicate="TemplateStyles:r140555418">.mw-parser-output .itwiki-template-occhiello{width:100%;line-height:25px;border:1px solid #CCF;background-color:#F0EEFF;box-sizing:border-box}.mw-parser-output .itwiki-template-occhiello-progetto{background-color:#FAFAFA}@media screen{html.skin-theme-clientpref-night .mw-parser-output .itwiki-template-occhiello{background-color:#202122;border-color:#54595D}html.skin-theme-clientpref-night .mw-parser-output .itwiki-template-occhiello-progetto{background-color:#282929}}@media screen and (prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .itwiki-template-occhiello{background-color:#202122;border-color:#54595D}html.skin-theme-clientpref-os .mw-parser-output .itwiki-template-occhiello-progetto{background-color:#282929}}</style><div class="itwiki-template-occhiello"><span class="noviewer" typeof="mw:File"><a href="/wiki/File:Crystal128-kmplot.svg" class="mw-file-description" title="Matematica"><img alt=" " src="//upload.wikimedia.org/wikipedia/commons/thumb/a/af/Crystal128-kmplot.svg/25px-Crystal128-kmplot.svg.png" decoding="async" width="25" height="25" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/a/af/Crystal128-kmplot.svg/38px-Crystal128-kmplot.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/a/af/Crystal128-kmplot.svg/50px-Crystal128-kmplot.svg.png 2x" data-file-width="245" data-file-height="244" /></a></span> <b><a href="/wiki/Portale:Matematica" title="Portale:Matematica">Portale Matematica</a></b>: accedi alle voci di Wikipedia che trattano di matematica</div></div></div>    </div><noscript><img src="https://login.wikimedia.org/wiki/Special:CentralAutoLogin/start?useformat=desktop&type=1x1&usesul3=0" alt="" width="1" height="1" style="border: none; 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