Compare 90 vs 91
| Property | 90 | 91 |
|---|---|---|
| Type | composite number | semiprime |
| Unique factors | 3 | 2 |
| Total factors | 4 | 2 |
| Prime factorization | 21 × 32 × 51 | 71 × 131 |
| Prime factorization | 2 × 3 × 3 × 5 | 7 × 13 |
| Divisors count | 12 | 4 |
| Divisors | 1, 2, 3, 5, 6, 9, 10, 15, 18, 30, 45, 90 | 1, 7, 13, 91 |
| Number of properties | 0 | 1 |
| Semiprimes | 31st | |
| Roman numberals | XC | XCI |
| Base 2 | 10110102 | 10110112 |
| Base 3 | 101003 | 101013 |
| Base 4 | 11224 | 11234 |
| Base 5 | 3305 | 3315 |
| Base 6 | 2306 | 2316 |
| Base 7 | 1567 | 1607 |
| Base 8 | 1328 | 1338 |
| Base 9 | 1109 | 1119 |
| Base 10 | 9010 | 9110 |
| Base 11 | 8211 | 8311 |
| Base 12 | 7612 | 7712 |
| Base 13 | 6c13 | 7013 |
| Base 14 | 6614 | 6714 |
| Base 15 | 6015 | 6115 |
| Base 16 | 5a16 | 5b16 |