| Nominal | 16991 |
| Cardinal | sixteen thousand nine hundred ninety-one |
Cardinal sixteen thousand nine hundred ninety-one | |
| Ordinal | 16,991st |
| Number of digits | 5 |
| Sum of digits | 26 |
| Product of digits | 486 |
| Number parity | Odd |
| Prime factorization | 13 x 1307 |
| Prime factors | 13, 1307 |
| Number of distinct prime factors ω(n) | 2 |
| Total number of prime factors Ω(n) | 2 |
| Sum of prime factors | 1320 |
| Product of prime factors | 16991 |
| Is 16991 a prime number? | No |
| Is 16991 a semiprime number? | Yes |
| Is 16991 a Chen prime number? | No |
| Is 16991 a Mersenne prime number? | No |
| Is 16991 a Catalan number? | No |
| Is 16991 a Fibonacci number? | No |
| Is 16991 a Idoneal number? | No |
| Square of 16991 (n2) | 288694081 |
| Cube of 16991 (n3) | 4905201130271 |
| Square root of 16991 | 130.34953011039 |
| Natural Logarithm (ln) of 16991 | 9.7404390710858 |
| Decimal Logarithm (log) of 16991 | 4.2302189398874 |
| Sine of 16991 | 0.95418659027512 |
| Cosecant of 16991 | 1.048013051317 |
| Cosine of 16991 | 0.29921221722908 |
| Secant of 16991 | 3.3421095209973 |
| Tangent of 16991 | 3.1889960881664 |
| Cotangent of 16991 | 0.31357830876957 |
| The spelling of 16991 in words is "sixteen thousand nine hundred ninety-one", meaning that: |
| 16991 is not an aban number (as it contains the letter a) |
| 16991 is not an eban number (as it contains the letter e) |
| 16991 is not an iban number (as it contains the letter i) |
| 16991 is not an oban number (as it contains the letter o) |
| 16991 is not a tban number (as it contains the letter t) |
| 16991 is not an uban number (as it contains the letter u) |
| Bengali numerals | ১৬৯৯১ |
| Eastern Arabic numerals | ١٦٬٩٩١ |
| Hieroglyphs numeralsused in Ancient Egypt | 𓂭𓆼𓆼𓆼𓆼𓆼𓆼𓍪𓎎𓏺 |
| Khmer numerals | ១៦៩៩១ |
| Japanese numerals | 一万六千九百九十一 |
| Roman numerals | n/a |
| Thai numerals | ๑๖๙๙๑ |
| Arabic | ستة عشر ألف و تسعة مائة و واحد و تسعون |
| Croatian | šesnaest tisuća devetsto devedeset i jedan |
| Czech | šestnáct tisíc devět set devadesát jeden |
| Danish | seksten tusinde ni hundrede en og halvfems |
| Dutch | zestienduizend negenhonderdéénennegentig |
| Estonian | akpe wuiade alafa asieke blaasieke vɔ ɖekɛ |
| Faroese | sekstan tusin og níggjuhundraðognítiein |
| Filipino | labíng-anim na libó’t siyám na daán at siyám na pû’t isá |
| Finnish | kuusitoistatuhattayhdeksänsataayhdeksänkymmentäyksi |
| French | seize mille neuf cent quatre-vingt-onze |
| Greek | δεκαέξι χίλιάδες εννιακόσια εννενήντα ένα |
| German | sechzehntausendneunhunderteinundneunzig |
| Hebrew | שישה עשר אלף תשע מאות תשעים ואחת |
| Hindi | सोलह हज़ार नौ सौ इक्यानबे |
| Hungarian | tizenhatezerkilencszázkilencvenegy |
| Icelandic | sextán þúsund og níuhundrað og níutíu og einn |
| Indonesian | enam belas ribu sembilan ratus sembilan puluh satu |
| Italian | sedicimilanovecentonovantuno |
| Japanese | 一万六千九百九十一 |
| Korean | 만 육천구백구십일 |
| Latvian | sešpadsmit tūkstoši deviņsimt deviņdesmit viens |
| Lithuanian | šešiolika tūkstančių devyni šimtai devyniasdešimt vienas |
| Norwegian | seksten tusen ni hundre og nittién |
| Persian | شانزده هزار و نهصد و نود و یک |
| Polish | szesnaście tysięcy dziewięćset dziewięćdziesiąt jeden |
| Portuguese | dezesseis mil novecentos e noventa e um |
| Romanian | şasesprezece mii nouă sute nouăzeci şi unu |
| Russian | шестнадцать тысяч девятьсот девяносто один |
| Serbian | шеснаест хиљада деветсто деведесет и један |
| Slovak | šestnásť tisíc deväťsto deväťdesiatjeden |
| Slovene | šestnajst tisuću devetsto devetdeset ena |
| Spanish | dieciseis mil novecientos noventa y uno |
| Swahili | elfu kumi na sita, mia tisa na tisini na moja |
| Swedish | sextontusenniohundranittioen |
| Thai | หนึ่งหมื่นหกพันเก้าร้อยเก้าสิบเอ็ด |
| Turkish | on altı bin dokuz yüz doksan bir |
| Ukrainian | шістнадцять тисяч девʼятсот девʼяносто один |
| Vietnamese | mười sáu nghìn chín trăm chín mươi mốt |
| Number 16991 reversed | 19961 | |
| Unicode Character | U+425F | 䉟 |
| Unix Timestamp | Thu, 01 Jan 1970 04:43:11 +0000 | |