| Nominal | 21840 |
| Cardinal | twenty-one thousand eight hundred forty |
Cardinal twenty-one thousand eight hundred forty | |
| Ordinal | 21,840th |
| Number of digits | 5 |
| Sum of digits | 15 |
| Product of digits | 0 |
| Number parity | Even |
| Prime factorization | 2 x 2 x 2 x 2 x 3 x 5 x 7 x 13 |
| Prime factorization in exponent form | 24 x 3 x 5 x 7 x 13 |
| Prime factors | 2, 3, 5, 7, 13 |
| Number of distinct prime factors ω(n) | 5 |
| Total number of prime factors Ω(n) | 8 |
| Sum of prime factors | 30 |
| Product of prime factors | 2730 |
| Is 21840 a prime number? | No |
| Is 21840 a semiprime number? | No |
| Is 21840 a Chen prime number? | No |
| Is 21840 a Mersenne prime number? | No |
| Is 21840 a Catalan number? | No |
| Is 21840 a Fibonacci number? | No |
| Is 21840 a Idoneal number? | No |
| Square of 21840 (n2) | 476985600 |
| Cube of 21840 (n3) | 10417365504000 |
| Square root of 21840 | 147.78362561529 |
| Natural Logarithm (ln) of 21840 | 9.9914984298588 |
| Decimal Logarithm (log) of 21840 | 4.3392526340327 |
| Sine of 21840 | -0.34489578589283 |
| Cosecant of 21840 | -2.8994265540569 |
| Cosine of 21840 | 0.93864098401538 |
| Secant of 21840 | 1.0653700584457 |
| Tangent of 21840 | -0.36744164357433 |
| Cotangent of 21840 | -2.7215205937803 |
| The spelling of 21840 in words is "twenty-one thousand eight hundred forty", meaning that: |
| 21840 is not an aban number (as it contains the letter a) |
| 21840 is not an eban number (as it contains the letter e) |
| 21840 is not an iban number (as it contains the letter i) |
| 21840 is not an oban number (as it contains the letter o) |
| 21840 is not a tban number (as it contains the letter t) |
| 21840 is not an uban number (as it contains the letter u) |
| Bengali numerals | ২১৮৪০ |
| Eastern Arabic numerals | ٢١٬٨٤٠ |
| Hieroglyphs numeralsused in Ancient Egypt | 𓂭𓂭𓆼𓍩𓎉 |
| Khmer numerals | ២១៨៤០ |
| Japanese numerals | 二万千八百四十 |
| Roman numerals | n/a |
| Thai numerals | ๒๑๘๔๐ |
| Arabic | واحد و عشرون ألف و ثمانية مائة و أربعون |
| Croatian | dvadeset i jedna tisuća osamsto četrdeset |
| Czech | dvacet jedna tisíc osm set čtyřicet |
| Danish | en og tyve tusinde otte hundrede fyrre |
| Dutch | éénentwintigduizend achthonderdveertig |
| Estonian | akpe blaeve vɔ ɖekɛ alafa enyi kple blaene |
| Faroese | tjúgoeitt tusin og áttahundraðogfýrati |
| Filipino | dalawáng pû’t isáng libó’t walóng daán at ápat na pû |
| Finnish | kaksikymmentäyksituhattakahdeksansataaneljäkymmentä |
| French | vingt et un mille huit cent quarante |
| Greek | είκοσι μία χίλιάδες οκτακόσια σαράντα |
| German | einundzwanzigtausendachthundertvierzig |
| Hebrew | עשרים ואחד אלף שמונה מאות ארבעים |
| Hindi | इक्कीस हज़ार आठ सौ चालीस |
| Hungarian | huszonegyezernyolcszáznegyven |
| Icelandic | tuttugu og eitt þúsund og áttahundrað og fjörutíu |
| Indonesian | dua puluh satu ribu delapan ratus empat puluh |
| Italian | ventunomilaottocentoquaranta |
| Japanese | 二万千八百四十 |
| Korean | 이만 천팔백사십 |
| Latvian | divdesmit viens tūkstoši astoņsimt četrdesmit |
| Lithuanian | dvidešimt vienas tūkstantis aštuoni šimtai keturiasdešimt |
| Norwegian | tjueett tusen åtte hundre og førti |
| Persian | بیست و یک هزار و هشتصد و چهل |
| Polish | dwadzieścia jeden tysięcy osiemset czterdzieści |
| Portuguese | vinte e um mil oitocentos e quarenta |
| Romanian | douăzeci şi una mii opt sute patruzeci |
| Russian | двадцать одна тысяча восемьсот сорок |
| Serbian | двадесет и једна хиљада осамсто четрдесет |
| Slovak | dvadsaťjedna tisíc osemsto štyridsať |
| Slovene | dvaset ena tisuću osemsto štirideset |
| Spanish | veintiún mil ochocientos cuarenta |
| Swahili | elfu ishirini na moja, mia nane na arobaini |
| Swedish | tjugoentusenåttahundrafyrtio |
| Thai | สองหมื่นหนึ่งพันแปดร้อยสี่สิบ |
| Turkish | yirmi bir bin sekiz yüz kırk |
| Ukrainian | двадцять одна тисяча вісімсот сорок |
| Vietnamese | hai mươi mốt nghìn tám trăm bốn mươi |
| Number 21840 reversed | 04812 | |
| Unicode Character | U+5550 | 啐 |
| Unix Timestamp | Thu, 01 Jan 1970 06:04:00 +0000 | |