Compare 16 vs 21
| Property | 16 | 21 |
|---|---|---|
| Type | composite number | semiprime |
| Unique factors | 1 | 2 |
| Total factors | 4 | 2 |
| Prime factorization | 24 | 31 × 71 |
| Prime factorization | 2 × 2 × 2 × 2 | 3 × 7 |
| Divisors count | 5 | 4 |
| Divisors | 1, 2, 4, 8, 16 | 1, 3, 7, 21 |
| Number of properties | 0 | 1 |
| Semiprimes | 7th | |
| Roman numberals | XVI | XXI |
| Base 2 | 100002 | 101012 |
| Base 3 | 1213 | 2103 |
| Base 4 | 1004 | 1114 |
| Base 5 | 315 | 415 |
| Base 6 | 246 | 336 |
| Base 7 | 227 | 307 |
| Base 8 | 208 | 258 |
| Base 9 | 179 | 239 |
| Base 10 | 1610 | 2110 |
| Base 11 | 1511 | 1a11 |
| Base 12 | 1412 | 1912 |
| Base 13 | 1313 | 1813 |
| Base 14 | 1214 | 1714 |
| Base 15 | 1115 | 1615 |
| Base 16 | 1016 | 1516 |