Compare 81 vs 85
| Property | 81 | 85 |
|---|---|---|
| Type | composite number | semiprime |
| Unique factors | 1 | 2 |
| Total factors | 4 | 2 |
| Prime factorization | 34 | 51 × 171 |
| Prime factorization | 3 × 3 × 3 × 3 | 5 × 17 |
| Divisors count | 5 | 4 |
| Divisors | 1, 3, 9, 27, 81 | 1, 5, 17, 85 |
| Number of properties | 0 | 1 |
| Semiprimes | 28th | |
| Roman numberals | LXXXI | LXXXV |
| Base 2 | 10100012 | 10101012 |
| Base 3 | 100003 | 100113 |
| Base 4 | 11014 | 11114 |
| Base 5 | 3115 | 3205 |
| Base 6 | 2136 | 2216 |
| Base 7 | 1447 | 1517 |
| Base 8 | 1218 | 1258 |
| Base 9 | 1009 | 1049 |
| Base 10 | 8110 | 8510 |
| Base 11 | 7411 | 7811 |
| Base 12 | 6912 | 7112 |
| Base 13 | 6313 | 6713 |
| Base 14 | 5b14 | 6114 |
| Base 15 | 5615 | 5a15 |
| Base 16 | 5116 | 5516 |