Compare 661 vs 757
| Property | 661 | 757 |
|---|---|---|
| Type | prime | prime |
| Unique factors | 1 | 1 |
| Total factors | 1 | 1 |
| Prime factorization | 6611 | 7571 |
| Prime factorization | 661 | 757 |
| Divisors count | 2 | 2 |
| Divisors | 1, 661 | 1, 757 |
| Number of properties | 5 | 8 |
| Additive primes | 65th | 71st |
| Centered decagonal primes | 8th | |
| Cousin primes (1st member) | 32nd | |
| Harmonic primes | 52nd | |
| Isolated primes | 75th | |
| Palindromic primes | 16th | |
| Primes | 121st | 134th |
| Pythagorean primes | 57th | 63rd |
| Sexy primes (2nd member) | 63rd | |
| Twin primes (2nd member) | 30th | |
| Roman numberals | DCLXI | DCCLVII |
| Base 2 | 10100101012 | 10111101012 |
| Base 3 | 2201113 | 10010013 |
| Base 4 | 221114 | 233114 |
| Base 5 | 101215 | 110125 |
| Base 6 | 30216 | 33016 |
| Base 7 | 16337 | 21317 |
| Base 8 | 12258 | 13658 |
| Base 9 | 8149 | 10319 |
| Base 10 | 66110 | 75710 |
| Base 11 | 55111 | 62911 |
| Base 12 | 47112 | 53112 |
| Base 13 | 3bb13 | 46313 |
| Base 14 | 35314 | 3c114 |
| Base 15 | 2e115 | 35715 |
| Base 16 | 29516 | 2f516 |