Compare 643 vs 649
| Property | 643 | 649 |
|---|---|---|
| Type | prime | semiprime |
| Unique factors | 1 | 2 |
| Total factors | 1 | 2 |
| Prime factorization | 6431 | 111 × 591 |
| Prime factorization | 643 | 11 × 59 |
| Divisors count | 2 | 4 |
| Divisors | 1, 643 | 1, 11, 59, 649 |
| Number of properties | 7 | 1 |
| Additive primes | 63rd | |
| Cousin primes (1st member) | 29th | |
| Left-truncatable primes | 38th | |
| Lucky primes | 33rd | |
| Primes | 117th | |
| Prime triplets (2nd member) | 24th | |
| Semiprimes | 196th | |
| Twin primes (2nd member) | 29th | |
| Roman numberals | DCXLIII | DCXLIX |
| Base 2 | 10100000112 | 10100010012 |
| Base 3 | 2122113 | 2200013 |
| Base 4 | 220034 | 220214 |
| Base 5 | 100335 | 100445 |
| Base 6 | 25516 | 30016 |
| Base 7 | 16067 | 16157 |
| Base 8 | 12038 | 12118 |
| Base 9 | 7849 | 8019 |
| Base 10 | 64310 | 64910 |
| Base 11 | 53511 | 54011 |
| Base 12 | 45712 | 46112 |
| Base 13 | 3a613 | 3ac13 |
| Base 14 | 33d14 | 34514 |
| Base 15 | 2cd15 | 2d415 |
| Base 16 | 28316 | 28916 |