Compare 10 vs 21
| Property | 10 | 21 |
|---|---|---|
| Type | semiprime | semiprime |
| Unique factors | 2 | 2 |
| Total factors | 2 | 2 |
| Prime factorization | 21 × 51 | 31 × 71 |
| Prime factorization | 2 × 5 | 3 × 7 |
| Divisors count | 4 | 4 |
| Divisors | 1, 2, 5, 10 | 1, 3, 7, 21 |
| Number of properties | 1 | 1 |
| Semiprimes | 4th | 7th |
| Roman numberals | X | XXI |
| Base 2 | 10102 | 101012 |
| Base 3 | 1013 | 2103 |
| Base 4 | 224 | 1114 |
| Base 5 | 205 | 415 |
| Base 6 | 146 | 336 |
| Base 7 | 137 | 307 |
| Base 8 | 128 | 258 |
| Base 9 | 119 | 239 |
| Base 10 | 1010 | 2110 |
| Base 11 | a11 | 1a11 |
| Base 12 | a12 | 1912 |
| Base 13 | a13 | 1813 |
| Base 14 | a14 | 1714 |
| Base 15 | a15 | 1615 |
| Base 16 | a16 | 1516 |