| Nominal | 21990 |
| Cardinal | twenty-one thousand nine hundred ninety |
Cardinal twenty-one thousand nine hundred ninety | |
| Ordinal | 21,990th |
| Number of digits | 5 |
| Sum of digits | 21 |
| Product of digits | 0 |
| Number parity | Even |
| Prime factorization | 2 x 3 x 5 x 733 |
| Prime factors | 2, 3, 5, 733 |
| Number of distinct prime factors ω(n) | 4 |
| Total number of prime factors Ω(n) | 4 |
| Sum of prime factors | 743 |
| Product of prime factors | 21990 |
| Is 21990 a prime number? | No |
| Is 21990 a semiprime number? | No |
| Is 21990 a Chen prime number? | No |
| Is 21990 a Mersenne prime number? | No |
| Is 21990 a Catalan number? | No |
| Is 21990 a Fibonacci number? | No |
| Is 21990 a Idoneal number? | No |
| Square of 21990 (n2) | 483560100 |
| Cube of 21990 (n3) | 10633486599000 |
| Square root of 21990 | 148.29025591724 |
| Natural Logarithm (ln) of 21990 | 9.9983430835488 |
| Decimal Logarithm (log) of 21990 | 4.3422252293608 |
| Sine of 21990 | -0.91218097179308 |
| Cosecant of 21990 | -1.0962736901147 |
| Cosine of 21990 | 0.4097875970532 |
| Secant of 21990 | 2.4402885963144 |
| Tangent of 21990 | -2.2259848232416 |
| Cotangent of 21990 | -0.44923936118474 |
| The spelling of 21990 in words is "twenty-one thousand nine hundred ninety", meaning that: |
| 21990 is not an aban number (as it contains the letter a) |
| 21990 is not an eban number (as it contains the letter e) |
| 21990 is not an iban number (as it contains the letter i) |
| 21990 is not an oban number (as it contains the letter o) |
| 21990 is not a tban number (as it contains the letter t) |
| 21990 is not an uban number (as it contains the letter u) |
| Bengali numerals | ২১৯৯০ |
| Eastern Arabic numerals | ٢١٬٩٩٠ |
| Hieroglyphs numeralsused in Ancient Egypt | 𓂭𓂭𓆼𓍪𓎎 |
| Khmer numerals | ២១៩៩០ |
| Japanese numerals | 二万千九百九十 |
| Roman numerals | n/a |
| Thai numerals | ๒๑๙๙๐ |
| Arabic | واحد و عشرون ألف و تسعة مائة و تسعون |
| Croatian | dvadeset i jedna tisuća devetsto devedeset |
| Czech | dvacet jedna tisíc devět set devadesát |
| Danish | en og tyve tusinde ni hundrede halvfems |
| Dutch | éénentwintigduizend negenhonderdnegentig |
| Estonian | akpe blaeve vɔ ɖekɛ alafa asieke kple blaasieke |
| Faroese | tjúgoeitt tusin og níggjuhundraðogníti |
| Filipino | dalawáng pû’t isáng libó’t siyám na daán at siyám na pû |
| Finnish | kaksikymmentäyksituhattayhdeksänsataayhdeksänkymmentä |
| French | vingt et un mille neuf cent quatre-vingt-dix |
| Greek | είκοσι μία χίλιάδες εννιακόσια εννενήντα |
| German | einundzwanzigtausendneunhundertneunzig |
| Hebrew | עשרים ואחד אלף תשע מאות תשעים |
| Hindi | इक्कीस हज़ार नौ सौ नब्बे |
| Hungarian | huszonegyezerkilencszázkilencven |
| Icelandic | tuttugu og eitt þúsund og níuhundrað og níutíu |
| Indonesian | dua puluh satu ribu sembilan ratus sembilan puluh |
| Italian | ventunomilanovecentonovanta |
| Japanese | 二万千九百九十 |
| Korean | 이만 천구백구십 |
| Latvian | divdesmit viens tūkstoši deviņsimt deviņdesmit |
| Lithuanian | dvidešimt vienas tūkstantis devyni šimtai devyniasdešimt |
| Norwegian | tjueett tusen ni hundre og nitti |
| Persian | بیست و یک هزار و نهصد و نود |
| Polish | dwadzieścia jeden tysięcy dziewięćset dziewięćdziesiąt |
| Portuguese | vinte e um mil novecentos e noventa |
| Romanian | douăzeci şi una mii nouă sute nouăzeci |
| Russian | двадцать одна тысяча девятьсот девяносто |
| Serbian | двадесет и једна хиљада деветсто деведесет |
| Slovak | dvadsaťjedna tisíc deväťsto deväťdesiat |
| Slovene | dvaset ena tisuću devetsto devetdeset |
| Spanish | veintiún mil novecientos noventa |
| Swahili | elfu ishirini na moja, mia tisa na tisini |
| Swedish | tjugoentusenniohundranittio |
| Thai | สองหมื่นหนึ่งพันเก้าร้อยเก้าสิบ |
| Turkish | yirmi bir bin dokuz yüz doksan |
| Ukrainian | двадцять одна тисяча девʼятсот девʼяносто |
| Vietnamese | hai mươi mốt nghìn chín trăm chín mươi |
| Number 21990 reversed | 09912 | |
| Unicode Character | U+55E6 | 嗦 |
| Unix Timestamp | Thu, 01 Jan 1970 06:06:30 +0000 | |