Compare 21 vs 63
| Property | 21 | 63 |
|---|---|---|
| Type | semiprime | composite number |
| Unique factors | 2 | 2 |
| Total factors | 2 | 3 |
| Prime factorization | 31 × 71 | 32 × 71 |
| Prime factorization | 3 × 7 | 3 × 3 × 7 |
| Divisors count | 4 | 6 |
| Divisors | 1, 3, 7, 21 | 1, 3, 7, 9, 21, 63 |
| Number of properties | 1 | 0 |
| Semiprimes | 7th | |
| Roman numberals | XXI | LXIII |
| Base 2 | 101012 | 1111112 |
| Base 3 | 2103 | 21003 |
| Base 4 | 1114 | 3334 |
| Base 5 | 415 | 2235 |
| Base 6 | 336 | 1436 |
| Base 7 | 307 | 1207 |
| Base 8 | 258 | 778 |
| Base 9 | 239 | 709 |
| Base 10 | 2110 | 6310 |
| Base 11 | 1a11 | 5811 |
| Base 12 | 1912 | 5312 |
| Base 13 | 1813 | 4b13 |
| Base 14 | 1714 | 4714 |
| Base 15 | 1615 | 4315 |
| Base 16 | 1516 | 3f16 |