Compare 642 vs 643
| Property | 642 | 643 |
|---|---|---|
| Type | composite number | prime |
| Unique factors | 3 | 1 |
| Total factors | 3 | 1 |
| Prime factorization | 21 × 31 × 1071 | 6431 |
| Prime factorization | 2 × 3 × 107 | 643 |
| Divisors count | 8 | 2 |
| Divisors | 1, 2, 3, 6, 107, 214, 321, 642 | 1, 643 |
| Number of properties | 0 | 7 |
| 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 | DCXLII | DCXLIII |
| Base 2 | 10100000102 | 10100000112 |
| Base 3 | 2122103 | 2122113 |
| Base 4 | 220024 | 220034 |
| Base 5 | 100325 | 100335 |
| Base 6 | 25506 | 25516 |
| Base 7 | 16057 | 16067 |
| Base 8 | 12028 | 12038 |
| Base 9 | 7839 | 7849 |
| Base 10 | 64210 | 64310 |
| Base 11 | 53411 | 53511 |
| Base 12 | 45612 | 45712 |
| Base 13 | 3a513 | 3a613 |
| Base 14 | 33c14 | 33d14 |
| Base 15 | 2cc15 | 2cd15 |
| Base 16 | 28216 | 28316 |