Compare 1661 vs 1666
| Property | 1661 | 1666 |
|---|---|---|
| Type | semiprime | composite number |
| Unique factors | 2 | 3 |
| Total factors | 2 | 4 |
| Prime factorization | 111 × 1511 | 21 × 72 × 171 |
| Prime factorization | 11 × 151 | 2 × 7 × 7 × 17 |
| Divisors count | 4 | 12 |
| Divisors | 1, 11, 151, 1661 | 1, 2, 7, 14, 17, 34, 49, 98, 119, 238, 833, 1666 |
| Number of properties | 1 | 0 |
| Semiprimes | 479th | |
| Roman numberals | MDCLXI | MDCLXVI |
| Base 2 | 110011111012 | 110100000102 |
| Base 3 | 20211123 | 20212013 |
| Base 4 | 1213314 | 1220024 |
| Base 5 | 231215 | 231315 |
| Base 6 | 114056 | 114146 |
| Base 7 | 45627 | 46007 |
| Base 8 | 31758 | 32028 |
| Base 9 | 22459 | 22519 |
| Base 10 | 166110 | 166610 |
| Base 11 | 128011 | 128511 |
| Base 12 | b6512 | b6a12 |
| Base 13 | 9aa13 | 9b213 |
| Base 14 | 86914 | 87014 |
| Base 15 | 75b15 | 76115 |
| Base 16 | 67d16 | 68216 |