Compare 643 vs 645
| Property | 643 | 645 |
|---|---|---|
| Type | prime | composite number |
| Unique factors | 1 | 3 |
| Total factors | 1 | 3 |
| Prime factorization | 6431 | 31 × 51 × 431 |
| Prime factorization | 643 | 3 × 5 × 43 |
| Divisors count | 2 | 8 |
| Divisors | 1, 643 | 1, 3, 5, 15, 43, 129, 215, 645 |
| Number of properties | 7 | 0 |
| Additive primes | 63rd | |
| Cousin primes (1st member) | 29th | |
| Left-truncatable primes | 38th | |
| Lucky primes | 33rd | |
| Primes | 117th | |
| Prime triplets (2nd member) | 24th | |
| Twin primes (2nd member) | 29th | |
| Roman numberals | DCXLIII | DCXLV |
| Base 2 | 10100000112 | 10100001012 |
| Base 3 | 2122113 | 2122203 |
| Base 4 | 220034 | 220114 |
| Base 5 | 100335 | 100405 |
| Base 6 | 25516 | 25536 |
| Base 7 | 16067 | 16117 |
| Base 8 | 12038 | 12058 |
| Base 9 | 7849 | 7869 |
| Base 10 | 64310 | 64510 |
| Base 11 | 53511 | 53711 |
| Base 12 | 45712 | 45912 |
| Base 13 | 3a613 | 3a813 |
| Base 14 | 33d14 | 34114 |
| Base 15 | 2cd15 | 2d015 |
| Base 16 | 28316 | 28516 |