Compare 639 vs 643
| Property | 639 | 643 |
|---|---|---|
| Type | composite number | prime |
| Unique factors | 2 | 1 |
| Total factors | 3 | 1 |
| Prime factorization | 32 × 711 | 6431 |
| Prime factorization | 3 × 3 × 71 | 643 |
| Divisors count | 6 | 2 |
| Divisors | 1, 3, 9, 71, 213, 639 | 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 | DCXXXIX | DCXLIII |
| Base 2 | 10011111112 | 10100000112 |
| Base 3 | 2122003 | 2122113 |
| Base 4 | 213334 | 220034 |
| Base 5 | 100245 | 100335 |
| Base 6 | 25436 | 25516 |
| Base 7 | 16027 | 16067 |
| Base 8 | 11778 | 12038 |
| Base 9 | 7809 | 7849 |
| Base 10 | 63910 | 64310 |
| Base 11 | 53111 | 53511 |
| Base 12 | 45312 | 45712 |
| Base 13 | 3a213 | 3a613 |
| Base 14 | 33914 | 33d14 |
| Base 15 | 2c915 | 2cd15 |
| Base 16 | 27f16 | 28316 |