Compare 1661 vs 1687
| Property | 1661 | 1687 |
|---|---|---|
| Type | semiprime | semiprime |
| Unique factors | 2 | 2 |
| Total factors | 2 | 2 |
| Prime factorization | 111 × 1511 | 71 × 2411 |
| Prime factorization | 11 × 151 | 7 × 241 |
| Divisors count | 4 | 4 |
| Divisors | 1, 11, 151, 1661 | 1, 7, 241, 1687 |
| Number of properties | 1 | 1 |
| Semiprimes | 479th | 486th |
| Roman numberals | MDCLXI | MDCLXXXVII |
| Base 2 | 110011111012 | 110100101112 |
| Base 3 | 20211123 | 20221113 |
| Base 4 | 1213314 | 1221134 |
| Base 5 | 231215 | 232225 |
| Base 6 | 114056 | 114516 |
| Base 7 | 45627 | 46307 |
| Base 8 | 31758 | 32278 |
| Base 9 | 22459 | 22749 |
| Base 10 | 166110 | 168710 |
| Base 11 | 128011 | 12a411 |
| Base 12 | b6512 | b8712 |
| Base 13 | 9aa13 | 9ca13 |
| Base 14 | 86914 | 88714 |
| Base 15 | 75b15 | 77715 |
| Base 16 | 67d16 | 69716 |