Compare 21985 vs 21991
| Property | 21985 | 21991 |
|---|---|---|
| Type | semiprime | prime |
| Unique factors | 2 | 1 |
| Total factors | 2 | 1 |
| Prime factorization | 51 × 43971 | 219911 |
| Prime factorization | 5 × 4397 | 21991 |
| Divisors count | 4 | 2 |
| Divisors | 1, 5, 4397, 21985 | 1, 21991 |
| Number of properties | 1 | 5 |
| Chen primes | 1208th | |
| Isolated primes | 1720th | |
| Primes | 2463rd | |
| Semiprimes | 5550th | |
| Sexy primes (1st member) | 742nd | |
| Sexy prime triplets (1st member) | 202nd | |
| Roman numberals | ||
| Base 2 | 1010101111000012 | 1010101111001112 |
| Base 3 | 10100110213 | 10100111113 |
| Base 4 | 111132014 | 111132134 |
| Base 5 | 12004205 | 12004315 |
| Base 6 | 2454416 | 2454516 |
| Base 7 | 1210457 | 1210547 |
| Base 8 | 527418 | 527478 |
| Base 9 | 331379 | 331449 |
| Base 10 | 2198510 | 2199110 |
| Base 11 | 1557711 | 1558211 |
| Base 12 | 1088112 | 1088712 |
| Base 13 | a01213 | a01813 |
| Base 14 | 802514 | 802b14 |
| Base 15 | 67aa15 | 67b115 |
| Base 16 | 55e116 | 55e716 |