Compare 1661 vs 1665
| Property | 1661 | 1665 |
|---|---|---|
| Type | semiprime | composite number |
| Unique factors | 2 | 3 |
| Total factors | 2 | 4 |
| Prime factorization | 111 × 1511 | 32 × 51 × 371 |
| Prime factorization | 11 × 151 | 3 × 3 × 5 × 37 |
| Divisors count | 4 | 12 |
| Divisors | 1, 11, 151, 1661 | 1, 3, 5, 9, 15, 37, 45, 111, 185, 333, 555, 1665 |
| Number of properties | 1 | 0 |
| Semiprimes | 479th | |
| Roman numberals | MDCLXI | MDCLXV |
| Base 2 | 110011111012 | 110100000012 |
| Base 3 | 20211123 | 20212003 |
| Base 4 | 1213314 | 1220014 |
| Base 5 | 231215 | 231305 |
| Base 6 | 114056 | 114136 |
| Base 7 | 45627 | 45667 |
| Base 8 | 31758 | 32018 |
| Base 9 | 22459 | 22509 |
| Base 10 | 166110 | 166510 |
| Base 11 | 128011 | 128411 |
| Base 12 | b6512 | b6912 |
| Base 13 | 9aa13 | 9b113 |
| Base 14 | 86914 | 86d14 |
| Base 15 | 75b15 | 76015 |
| Base 16 | 67d16 | 68116 |