Compare 640 vs 641
| Property | 640 | 641 |
|---|---|---|
| Type | composite number | prime |
| Unique factors | 2 | 1 |
| Total factors | 8 | 1 |
| Prime factorization | 27 × 51 | 6411 |
| Prime factorization | 2 × 2 × 2 × 2 × 2 × 2 × 2 × 5 | 641 |
| Divisors count | 16 | 2 |
| Divisors | 1, 2, 4, 5, 8, 10, 16, 20, 32, 40, 64, 80, 128, 160, 320, 640 | 1, 641 |
| Number of properties | 0 | 14 |
| Additive primes | 62nd | |
| Chen primes | 81st | |
| Good primes | 35th | |
| Primes | 116th | |
| Prime triplets (1st member) | 24th | |
| Proth primes | 14th | |
| Pythagorean primes | 55th | |
| Quartan primes | 6th | |
| Sexy primes (1st member) | 57th | |
| Sexy prime quadrupletss (1st member) | 7th | |
| Sexy prime triplets (1st member) | 24th | |
| Solinas primes | 41st | |
| Sophie germain primes | 28th | |
| Twin primes (1st member) | 29th | |
| Roman numberals | DCXL | DCXLI |
| Base 2 | 10100000002 | 10100000012 |
| Base 3 | 2122013 | 2122023 |
| Base 4 | 220004 | 220014 |
| Base 5 | 100305 | 100315 |
| Base 6 | 25446 | 25456 |
| Base 7 | 16037 | 16047 |
| Base 8 | 12008 | 12018 |
| Base 9 | 7819 | 7829 |
| Base 10 | 64010 | 64110 |
| Base 11 | 53211 | 53311 |
| Base 12 | 45412 | 45512 |
| Base 13 | 3a313 | 3a413 |
| Base 14 | 33a14 | 33b14 |
| Base 15 | 2ca15 | 2cb15 |
| Base 16 | 28016 | 28116 |