Compare 661 vs 719
| Property | 661 | 719 |
|---|---|---|
| Type | prime | prime |
| Unique factors | 1 | 1 |
| Total factors | 1 | 1 |
| Prime factorization | 6611 | 7191 |
| Prime factorization | 661 | 719 |
| Divisors count | 2 | 2 |
| Divisors | 1, 661 | 1, 719 |
| Number of properties | 5 | 8 |
| Additive primes | 65th | 67th |
| Centered decagonal primes | 8th | |
| Chen primes | 88th | |
| Factorial primes | 6th | |
| Isolated primes | 69th | |
| Primes | 121st | 128th |
| Pythagorean primes | 57th | |
| Right-truncatable primes | 24th | |
| Safe primes | 21st | |
| Sophie germain primes | 32nd | |
| Twin primes (2nd member) | 30th | |
| Roman numberals | DCLXI | DCCXIX |
| Base 2 | 10100101012 | 10110011112 |
| Base 3 | 2201113 | 2221223 |
| Base 4 | 221114 | 230334 |
| Base 5 | 101215 | 103345 |
| Base 6 | 30216 | 31556 |
| Base 7 | 16337 | 20457 |
| Base 8 | 12258 | 13178 |
| Base 9 | 8149 | 8789 |
| Base 10 | 66110 | 71910 |
| Base 11 | 55111 | 5a411 |
| Base 12 | 47112 | 4bb12 |
| Base 13 | 3bb13 | 43413 |
| Base 14 | 35314 | 39514 |
| Base 15 | 2e115 | 32e15 |
| Base 16 | 29516 | 2cf16 |