| Nominal | 15991 |
| Cardinal | fifteen thousand nine hundred ninety-one |
Cardinal fifteen thousand nine hundred ninety-one | |
| Ordinal | 15,991st |
| Number of digits | 5 |
| Sum of digits | 25 |
| Product of digits | 405 |
| Number parity | Odd |
| Prime factorization | 15991 |
| Prime factors | 15991 |
| Number of distinct prime factors ω(n) | 1 |
| Total number of prime factors Ω(n) | 1 |
| Sum of prime factors | 15991 |
| Product of prime factors | 15991 |
| Is 15991 a prime number? | Yes |
| Is 15991 a semiprime number? | No |
| Is 15991 a Chen prime number? | No |
| Is 15991 a Mersenne prime number? | No |
| Is 15991 a Catalan number? | No |
| Is 15991 a Fibonacci number? | No |
| Is 15991 a Idoneal number? | No |
| Square of 15991 (n2) | 255712081 |
| Cube of 15991 (n3) | 4089091887271 |
| Square root of 15991 | 126.45552577883 |
| Natural Logarithm (ln) of 15991 | 9.6797813429594 |
| Decimal Logarithm (log) of 15991 | 4.2038756232773 |
| Sine of 15991 | 0.28920211254396 |
| Cosecant of 15991 | 3.4577894027244 |
| Cosine of 15991 | 0.95726805968867 |
| Secant of 15991 | 1.0446394715449 |
| Tangent of 15991 | 0.30211194201759 |
| Cotangent of 15991 | 3.310031352358 |
| The spelling of 15991 in words is "fifteen thousand nine hundred ninety-one", meaning that: |
| 15991 is not an aban number (as it contains the letter a) |
| 15991 is not an eban number (as it contains the letter e) |
| 15991 is not an iban number (as it contains the letter i) |
| 15991 is not an oban number (as it contains the letter o) |
| 15991 is not a tban number (as it contains the letter t) |
| 15991 is not an uban number (as it contains the letter u) |
| Bengali numerals | ১৫৯৯১ |
| Eastern Arabic numerals | ١٥٬٩٩١ |
| Hieroglyphs numeralsused in Ancient Egypt | 𓂭𓆼𓆼𓆼𓆼𓆼𓍪𓎎𓏺 |
| Khmer numerals | ១៥៩៩១ |
| Japanese numerals | 一万五千九百九十一 |
| Roman numerals | n/a |
| Thai numerals | ๑๕๙๙๑ |
| Arabic | خمسة عشر ألف و تسعة مائة و واحد و تسعون |
| Croatian | petnaest tisuća devetsto devedeset i jedan |
| Czech | patnáct tisíc devět set devadesát jeden |
| Danish | femten tusinde ni hundrede en og halvfems |
| Dutch | vijftienduizend negenhonderdéénennegentig |
| Estonian | akpe wuiatɔ̃ alafa asieke blaasieke vɔ ɖekɛ |
| Faroese | fímtan tusin og níggjuhundraðognítiein |
| Filipino | labíng-limáng libó’t siyám na daán at siyám na pû’t isá |
| Finnish | viisitoistatuhattayhdeksänsataayhdeksänkymmentäyksi |
| French | quinze mille neuf cent quatre-vingt-onze |
| Greek | δεκαπέντε χίλιάδες εννιακόσια εννενήντα ένα |
| German | fünfzehntausendneunhunderteinundneunzig |
| Hebrew | חמישה עשר אלף תשע מאות תשעים ואחת |
| Hindi | पन्द्रह हज़ार नौ सौ इक्यानबे |
| Hungarian | tizenötezerkilencszázkilencvenegy |
| Icelandic | fimmtán þúsund og níuhundrað og níutíu og einn |
| Indonesian | lima belas ribu sembilan ratus sembilan puluh satu |
| Italian | quindicimilanovecentonovantuno |
| Japanese | 一万五千九百九十一 |
| Korean | 만 오천구백구십일 |
| Latvian | piecpadsmit tūkstoši deviņsimt deviņdesmit viens |
| Lithuanian | penkiolika tūkstančių devyni šimtai devyniasdešimt vienas |
| Norwegian | femten tusen ni hundre og nittién |
| Persian | پانزده هزار و نهصد و نود و یک |
| Polish | piętnaście tysięcy dziewięćset dziewięćdziesiąt jeden |
| Portuguese | quinze mil novecentos e noventa e um |
| Romanian | cincisprezece mii nouă sute nouăzeci şi unu |
| Russian | пятнадцать тысяч девятьсот девяносто один |
| Serbian | петнаест хиљада деветсто деведесет и један |
| Slovak | pätnásť tisíc deväťsto deväťdesiatjeden |
| Slovene | petnajst tisuću devetsto devetdeset ena |
| Spanish | quince mil novecientos noventa y uno |
| Swahili | elfu kumi na tano, mia tisa na tisini na moja |
| Swedish | femtontusenniohundranittioen |
| Thai | หนึ่งหมื่นห้าพันเก้าร้อยเก้าสิบเอ็ด |
| Turkish | on beş bin dokuz yüz doksan bir |
| Ukrainian | пʼятнадцять тисяч девʼятсот девʼяносто один |
| Vietnamese | mười lăm nghìn chín trăm chín mươi mốt |
| Number 15991 reversed | 19951 | |
| Unicode Character | U+3E77 | 㹷 |
| Unix Timestamp | Thu, 01 Jan 1970 04:26:31 +0000 | |