Compare 645 vs 653
| Property | 645 | 653 |
|---|---|---|
| Type | composite number | prime |
| Unique factors | 3 | 1 |
| Total factors | 3 | 1 |
| Prime factorization | 31 × 51 × 431 | 6531 |
| Prime factorization | 3 × 5 × 43 | 653 |
| Divisors count | 8 | 2 |
| Divisors | 1, 3, 5, 15, 43, 129, 215, 645 | 1, 653 |
| Number of properties | 0 | 13 |
| Chen primes | 83rd | |
| Happy primes | 26th | |
| Harmonic primes | 48th | |
| Isolated primes | 62nd | |
| Left-truncatable primes | 40th | |
| Primes | 119th | |
| Pythagorean primes | 56th | |
| Sexy primes (1st member) | 59th | |
| Sexy primes (2nd member) | 58th | |
| Sexy prime quadrupletss (3rd member) | 7th | |
| Sexy prime triplets (2nd member) | 25th | |
| Sexy prime triplets (3rd member) | 24th | |
| Sophie germain primes | 29th | |
| Roman numberals | DCXLV | DCLIII |
| Base 2 | 10100001012 | 10100011012 |
| Base 3 | 2122203 | 2200123 |
| Base 4 | 220114 | 220314 |
| Base 5 | 100405 | 101035 |
| Base 6 | 25536 | 30056 |
| Base 7 | 16117 | 16227 |
| Base 8 | 12058 | 12158 |
| Base 9 | 7869 | 8059 |
| Base 10 | 64510 | 65310 |
| Base 11 | 53711 | 54411 |
| Base 12 | 45912 | 46512 |
| Base 13 | 3a813 | 3b313 |
| Base 14 | 34114 | 34914 |
| Base 15 | 2d015 | 2d815 |
| Base 16 | 28516 | 28d16 |