| Nominal | 18661 |
| Cardinal | eighteen thousand six hundred sixty-one |
Cardinal eighteen thousand six hundred sixty-one | |
| Ordinal | 18,661st |
| Number of digits | 5 |
| Sum of digits | 22 |
| Product of digits | 288 |
| Number parity | Odd |
| Prime factorization | 18661 |
| Prime factors | 18661 |
| Number of distinct prime factors ω(n) | 1 |
| Total number of prime factors Ω(n) | 1 |
| Sum of prime factors | 18661 |
| Product of prime factors | 18661 |
| Is 18661 a prime number? | Yes |
| Is 18661 a semiprime number? | No |
| Is 18661 a Chen prime number? | Yes |
| Is 18661 a Mersenne prime number? | No |
| Is 18661 a Catalan number? | No |
| Is 18661 a Fibonacci number? | No |
| Is 18661 a Idoneal number? | No |
| Square of 18661 (n2) | 348232921 |
| Cube of 18661 (n3) | 6498374538781 |
| Square root of 18661 | 136.60527076215 |
| Natural Logarithm (ln) of 18661 | 9.8341910635335 |
| Decimal Logarithm (log) of 18661 | 4.2709349128749 |
| Sine of 18661 | -0.060325673920945 |
| Cosecant of 18661 | -16.576690072463 |
| Cosine of 18661 | 0.99817874805367 |
| Secant of 18661 | 1.001824574957 |
| Tangent of 18661 | -0.060435742634847 |
| Cotangent of 18661 | -16.546499743405 |
| The spelling of 18661 in words is "eighteen thousand six hundred sixty-one", meaning that: |
| 18661 is not an aban number (as it contains the letter a) |
| 18661 is not an eban number (as it contains the letter e) |
| 18661 is not an iban number (as it contains the letter i) |
| 18661 is not an oban number (as it contains the letter o) |
| 18661 is not a tban number (as it contains the letter t) |
| 18661 is not an uban number (as it contains the letter u) |
| Bengali numerals | ১৮৬৬১ |
| Eastern Arabic numerals | ١٨٬٦٦١ |
| Hieroglyphs numeralsused in Ancient Egypt | 𓂭𓆼𓆼𓆼𓆼𓆼𓆼𓆼𓆼𓍧𓎋𓏺 |
| Khmer numerals | ១៨៦៦១ |
| Japanese numerals | 一万八千六百六十一 |
| Roman numerals | n/a |
| Thai numerals | ๑๘๖๖๑ |
| Arabic | ثمانية عشر ألف و ستة مائة و واحد و ستون |
| Croatian | osamnaest tisuća šeststo šezdeset i jedan |
| Czech | osmnáct tisíc šest set šedesát jeden |
| Danish | atten tusinde seks hundrede en og tres |
| Dutch | achttienduizend zeshonderdéénenzestig |
| Estonian | akpe wuienyi alafa ade blaade vɔ ɖekɛ |
| Faroese | átjan tusin og sekshundraðogsekstiein |
| Filipino | labíng-walóng libó’t anim na daán at anim na pû’t isá |
| Finnish | kahdeksantoistatuhattakuusisataakuusikymmentäyksi |
| French | dix-huit mille six cent soixante et un |
| Greek | δεκαοκτώ χίλιάδες εξακόσια εξήντα ένα |
| German | achtzehntausendsechshunderteinundsechzig |
| Hebrew | שמונה עשר אלף שש מאות שישים ואחת |
| Hindi | अठारह हज़ार छह सौ इकसठ |
| Hungarian | tizennyolcezerhatszázhatvanegy |
| Icelandic | átján þúsund og sexhundrað og sextíu og einn |
| Indonesian | delapan belas ribu enam ratus enam puluh satu |
| Italian | diciottomilaseicentosessantuno |
| Japanese | 一万八千六百六十一 |
| Korean | 만 팔천육백육십일 |
| Latvian | astoņpadsmit tūkstoši sešsimt sešdesmit viens |
| Lithuanian | aštuoniolika tūkstančių šeši šimtai šešiasdešimt vienas |
| Norwegian | atten tusen seks hundre og sekstién |
| Persian | هجده هزار و ششصد و شصت و یک |
| Polish | osiemnaście tysięcy sześćset sześćdziesiąt jeden |
| Portuguese | dezoito mil seiscentos e sessenta e um |
| Romanian | optsprezece mii şase sute şasezeci şi unu |
| Russian | восемнадцать тысяч шестьсот шестьдесят один |
| Serbian | осамнаест хиљада шестсто шездесет и један |
| Slovak | osemnásť tisíc šesťsto šesťdesiatjeden |
| Slovene | asemnajst tisuću šesto šestdeset ena |
| Spanish | dieciocho mil seiscientos sesenta y uno |
| Swahili | elfu kumi na nane, mia sita na sitini na moja |
| Swedish | artontusensexhundrasextioen |
| Thai | หนึ่งหมื่นแปดพันหกร้อยหกสิบเอ็ด |
| Turkish | on sekiz bin altı yüz altmış bir |
| Ukrainian | вісімнадцять тисяч шістсот шістдесят один |
| Vietnamese | mười tám nghìn sáu trăm sáu mươi mốt |
| Number 18661 reversed | 16681 | |
| Unicode Character | U+48E5 | 䣥 |
| Unix Timestamp | Thu, 01 Jan 1970 05:11:01 +0000 | |