Compare 81 vs 90
| Property | 81 | 90 |
|---|---|---|
| Type | composite number | composite number |
| Unique factors | 1 | 3 |
| Total factors | 4 | 4 |
| Prime factorization | 34 | 21 × 32 × 51 |
| Prime factorization | 3 × 3 × 3 × 3 | 2 × 3 × 3 × 5 |
| Divisors count | 5 | 12 |
| Divisors | 1, 3, 9, 27, 81 | 1, 2, 3, 5, 6, 9, 10, 15, 18, 30, 45, 90 |
| Number of properties | 0 | 0 |
| Roman numberals | LXXXI | XC |
| Base 2 | 10100012 | 10110102 |
| Base 3 | 100003 | 101003 |
| Base 4 | 11014 | 11224 |
| Base 5 | 3115 | 3305 |
| Base 6 | 2136 | 2306 |
| Base 7 | 1447 | 1567 |
| Base 8 | 1218 | 1328 |
| Base 9 | 1009 | 1109 |
| Base 10 | 8110 | 9010 |
| Base 11 | 7411 | 8211 |
| Base 12 | 6912 | 7612 |
| Base 13 | 6313 | 6c13 |
| Base 14 | 5b14 | 6614 |
| Base 15 | 5615 | 6015 |
| Base 16 | 5116 | 5a16 |