Compare 191221 vs 191231
| Property | 191221 | 191231 |
|---|---|---|
| Type | semiprime | prime |
| Unique factors | 2 | 1 |
| Total factors | 2 | 1 |
| Prime factorization | 431 × 44471 | 1912311 |
| Prime factorization | 43 × 4447 | 191231 |
| Divisors count | 4 | 2 |
| Divisors | 1, 43, 4447, 191221 | 1, 191231 |
| Number of properties | 1 | 7 |
| Additive primes | 6981st | |
| Cousin primes (2nd member) | 2049th | |
| Happy primes | 2654th | |
| Isolated primes | 13103rd | |
| Primes | 17264th | |
| Semiprimes | 43349th | |
| Sexy primes (1st member) | 4131st | |
| Sophie germain primes | 1981st | |
| Roman numberals | ||
| Base 2 | 1011101010111101012 | 1011101010111111112 |
| Base 3 | 1002010220213 | 1002010221223 |
| Base 4 | 2322233114 | 2322233334 |
| Base 5 | 221043415 | 221044115 |
| Base 6 | 40331416 | 40331556 |
| Base 7 | 14243327 | 14243457 |
| Base 8 | 5653658 | 5653778 |
| Base 9 | 3212679 | 3212789 |
| Base 10 | 19122110 | 19123110 |
| Base 11 | 12073811 | 12074711 |
| Base 12 | 927b112 | 927bb12 |
| Base 13 | 6906413 | 6907113 |
| Base 14 | 4d98914 | 4d99514 |
| Base 15 | 3b9d115 | 3b9db15 |
| Base 16 | 2eaf516 | 2eaff16 |