Compare 21 vs 25
| Property | 21 | 25 |
|---|---|---|
| Type | semiprime | semiprime |
| Unique factors | 2 | 1 |
| Total factors | 2 | 2 |
| Prime factorization | 31 × 71 | 52 |
| Prime factorization | 3 × 7 | 5 × 5 |
| Divisors count | 4 | 3 |
| Divisors | 1, 3, 7, 21 | 1, 5, 25 |
| Number of properties | 1 | 1 |
| Semiprimes | 7th | 9th |
| Roman numberals | XXI | XXV |
| Base 2 | 101012 | 110012 |
| Base 3 | 2103 | 2213 |
| Base 4 | 1114 | 1214 |
| Base 5 | 415 | 1005 |
| Base 6 | 336 | 416 |
| Base 7 | 307 | 347 |
| Base 8 | 258 | 318 |
| Base 9 | 239 | 279 |
| Base 10 | 2110 | 2510 |
| Base 11 | 1a11 | 2311 |
| Base 12 | 1912 | 2112 |
| Base 13 | 1813 | 1c13 |
| Base 14 | 1714 | 1b14 |
| Base 15 | 1615 | 1a15 |
| Base 16 | 1516 | 1916 |