Compare 631 vs 661
| Property | 631 | 661 |
|---|---|---|
| Type | prime | prime |
| Unique factors | 1 | 1 |
| Total factors | 1 | 1 |
| Prime factorization | 6311 | 6611 |
| Prime factorization | 631 | 661 |
| Divisors count | 2 | 2 |
| Divisors | 1, 631 | 1, 661 |
| Number of properties | 6 | 5 |
| Additive primes | 65th | |
| Centered decagonal primes | 8th | |
| Centered triangular primes | 7th | |
| Chen primes | 80th | |
| Cuban primes 1 | 10th | |
| Isolated primes | 60th | |
| Lucky primes | 32nd | |
| Primes | 115th | 121st |
| Pythagorean primes | 57th | |
| Twin primes (2nd member) | 30th | |
| Roman numberals | DCXXXI | DCLXI |
| Base 2 | 10011101112 | 10100101012 |
| Base 3 | 2121013 | 2201113 |
| Base 4 | 213134 | 221114 |
| Base 5 | 100115 | 101215 |
| Base 6 | 25316 | 30216 |
| Base 7 | 15617 | 16337 |
| Base 8 | 11678 | 12258 |
| Base 9 | 7719 | 8149 |
| Base 10 | 63110 | 66110 |
| Base 11 | 52411 | 55111 |
| Base 12 | 44712 | 47112 |
| Base 13 | 39713 | 3bb13 |
| Base 14 | 33114 | 35314 |
| Base 15 | 2c115 | 2e115 |
| Base 16 | 27716 | 29516 |