Compare 643 vs 646
| Property | 643 | 646 |
|---|---|---|
| Type | prime | composite number |
| Unique factors | 1 | 3 |
| Total factors | 1 | 3 |
| Prime factorization | 6431 | 21 × 171 × 191 |
| Prime factorization | 643 | 2 × 17 × 19 |
| Divisors count | 2 | 8 |
| Divisors | 1, 643 | 1, 2, 17, 19, 34, 38, 323, 646 |
| 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 | DCXLVI |
| Base 2 | 10100000112 | 10100001102 |
| Base 3 | 2122113 | 2122213 |
| Base 4 | 220034 | 220124 |
| Base 5 | 100335 | 100415 |
| Base 6 | 25516 | 25546 |
| Base 7 | 16067 | 16127 |
| Base 8 | 12038 | 12068 |
| Base 9 | 7849 | 7879 |
| Base 10 | 64310 | 64610 |
| Base 11 | 53511 | 53811 |
| Base 12 | 45712 | 45a12 |
| Base 13 | 3a613 | 3a913 |
| Base 14 | 33d14 | 34214 |
| Base 15 | 2cd15 | 2d115 |
| Base 16 | 28316 | 28616 |