Compare 640 vs 649
| Property | 640 | 649 |
|---|---|---|
| Type | composite number | semiprime |
| Unique factors | 2 | 2 |
| Total factors | 8 | 2 |
| Prime factorization | 27 × 51 | 111 × 591 |
| Prime factorization | 2 × 2 × 2 × 2 × 2 × 2 × 2 × 5 | 11 × 59 |
| Divisors count | 16 | 4 |
| Divisors | 1, 2, 4, 5, 8, 10, 16, 20, 32, 40, 64, 80, 128, 160, 320, 640 | 1, 11, 59, 649 |
| Number of properties | 0 | 1 |
| Semiprimes | 196th | |
| Roman numberals | DCXL | DCXLIX |
| Base 2 | 10100000002 | 10100010012 |
| Base 3 | 2122013 | 2200013 |
| Base 4 | 220004 | 220214 |
| Base 5 | 100305 | 100445 |
| Base 6 | 25446 | 30016 |
| Base 7 | 16037 | 16157 |
| Base 8 | 12008 | 12118 |
| Base 9 | 7819 | 8019 |
| Base 10 | 64010 | 64910 |
| Base 11 | 53211 | 54011 |
| Base 12 | 45412 | 46112 |
| Base 13 | 3a313 | 3ac13 |
| Base 14 | 33a14 | 34514 |
| Base 15 | 2ca15 | 2d415 |
| Base 16 | 28016 | 28916 |