Compare 18 vs 51
| Property | 18 | 51 |
|---|---|---|
| Type | composite number | semiprime |
| Unique factors | 2 | 2 |
| Total factors | 3 | 2 |
| Prime factorization | 21 × 32 | 31 × 171 |
| Prime factorization | 2 × 3 × 3 | 3 × 17 |
| Divisors count | 6 | 4 |
| Divisors | 1, 2, 3, 6, 9, 18 | 1, 3, 17, 51 |
| Number of properties | 0 | 1 |
| Semiprimes | 18th | |
| Roman numberals | XVIII | LI |
| Base 2 | 100102 | 1100112 |
| Base 3 | 2003 | 12203 |
| Base 4 | 1024 | 3034 |
| Base 5 | 335 | 2015 |
| Base 6 | 306 | 1236 |
| Base 7 | 247 | 1027 |
| Base 8 | 228 | 638 |
| Base 9 | 209 | 569 |
| Base 10 | 1810 | 5110 |
| Base 11 | 1711 | 4711 |
| Base 12 | 1612 | 4312 |
| Base 13 | 1513 | 3c13 |
| Base 14 | 1414 | 3914 |
| Base 15 | 1315 | 3615 |
| Base 16 | 1216 | 3316 |