Compare 21987 vs 21997
| Property | 21987 | 21997 |
|---|---|---|
| Type | composite number | prime |
| Unique factors | 3 | 1 |
| Total factors | 4 | 1 |
| Prime factorization | 32 × 71 × 3491 | 219971 |
| Prime factorization | 3 × 3 × 7 × 349 | 21997 |
| Divisors count | 12 | 2 |
| Divisors | 1, 3, 7, 9, 21, 63, 349, 1047, 2443, 3141, 7329, 21987 | 1, 21997 |
| Number of properties | 0 | 8 |
| Chen primes | 1209th | |
| Isolated primes | 1721st | |
| Left-truncatable primes | 173rd | |
| Primes | 2464th | |
| Pythagorean primes | 1223rd | |
| Sexy primes (1st member) | 743rd | |
| Sexy primes (2nd member) | 742nd | |
| Sexy prime triplets (2nd member) | 202nd | |
| Roman numberals | ||
| Base 2 | 1010101111000112 | 1010101111011012 |
| Base 3 | 10100111003 | 10100112013 |
| Base 4 | 111132034 | 111132314 |
| Base 5 | 12004225 | 12004425 |
| Base 6 | 2454436 | 2455016 |
| Base 7 | 1210507 | 1210637 |
| Base 8 | 527438 | 527558 |
| Base 9 | 331409 | 331519 |
| Base 10 | 2198710 | 2199710 |
| Base 11 | 1557911 | 1558811 |
| Base 12 | 1088312 | 1089112 |
| Base 13 | a01413 | a02113 |
| Base 14 | 802714 | 803314 |
| Base 15 | 67ac15 | 67b715 |
| Base 16 | 55e316 | 55ed16 |