Compare 1661 vs 1667
| Property | 1661 | 1667 |
|---|---|---|
| Type | semiprime | prime |
| Unique factors | 2 | 1 |
| Total factors | 2 | 1 |
| Prime factorization | 111 × 1511 | 16671 |
| Prime factorization | 11 × 151 | 1667 |
| Divisors count | 4 | 2 |
| Divisors | 1, 11, 151, 1661 | 1, 1667 |
| Number of properties | 1 | 6 |
| Chen primes | 165th | |
| Cousin primes (2nd member) | 59th | |
| Harmonic primes | 92nd | |
| Primes | 262nd | |
| Prime triplets (2nd member) | 43rd | |
| Semiprimes | 479th | |
| Twin primes (1st member) | 53rd | |
| Roman numberals | MDCLXI | MDCLXVII |
| Base 2 | 110011111012 | 110100000112 |
| Base 3 | 20211123 | 20212023 |
| Base 4 | 1213314 | 1220034 |
| Base 5 | 231215 | 231325 |
| Base 6 | 114056 | 114156 |
| Base 7 | 45627 | 46017 |
| Base 8 | 31758 | 32038 |
| Base 9 | 22459 | 22529 |
| Base 10 | 166110 | 166710 |
| Base 11 | 128011 | 128611 |
| Base 12 | b6512 | b6b12 |
| Base 13 | 9aa13 | 9b313 |
| Base 14 | 86914 | 87114 |
| Base 15 | 75b15 | 76215 |
| Base 16 | 67d16 | 68316 |