Compare 689 vs 691
| Property | 689 | 691 |
|---|---|---|
| Type | semiprime | prime |
| Unique factors | 2 | 1 |
| Total factors | 2 | 1 |
| Prime factorization | 131 × 531 | 6911 |
| Prime factorization | 13 × 53 | 691 |
| Divisors count | 4 | 2 |
| Divisors | 1, 13, 53, 689 | 1, 691 |
| Number of properties | 1 | 3 |
| Harmonic primes | 50th | |
| Isolated primes | 66th | |
| Primes | 125th | |
| Semiprimes | 207th | |
| Roman numberals | DCLXXXIX | DCXCI |
| Base 2 | 10101100012 | 10101100112 |
| Base 3 | 2211123 | 2211213 |
| Base 4 | 223014 | 223034 |
| Base 5 | 102245 | 102315 |
| Base 6 | 31056 | 31116 |
| Base 7 | 20037 | 20057 |
| Base 8 | 12618 | 12638 |
| Base 9 | 8459 | 8479 |
| Base 10 | 68910 | 69110 |
| Base 11 | 57711 | 57911 |
| Base 12 | 49512 | 49712 |
| Base 13 | 41013 | 41213 |
| Base 14 | 37314 | 37514 |
| Base 15 | 30e15 | 31115 |
| Base 16 | 2b116 | 2b316 |