Compare 643 vs 691
| Property | 643 | 691 |
|---|---|---|
| Type | prime | prime |
| Unique factors | 1 | 1 |
| Total factors | 1 | 1 |
| Prime factorization | 6431 | 6911 |
| Prime factorization | 643 | 691 |
| Divisors count | 2 | 2 |
| Divisors | 1, 643 | 1, 691 |
| Number of properties | 7 | 3 |
| Additive primes | 63rd | |
| Cousin primes (1st member) | 29th | |
| Harmonic primes | 50th | |
| Isolated primes | 66th | |
| Left-truncatable primes | 38th | |
| Lucky primes | 33rd | |
| Primes | 117th | 125th |
| Prime triplets (2nd member) | 24th | |
| Twin primes (2nd member) | 29th | |
| Roman numberals | DCXLIII | DCXCI |
| Base 2 | 10100000112 | 10101100112 |
| Base 3 | 2122113 | 2211213 |
| Base 4 | 220034 | 223034 |
| Base 5 | 100335 | 102315 |
| Base 6 | 25516 | 31116 |
| Base 7 | 16067 | 20057 |
| Base 8 | 12038 | 12638 |
| Base 9 | 7849 | 8479 |
| Base 10 | 64310 | 69110 |
| Base 11 | 53511 | 57911 |
| Base 12 | 45712 | 49712 |
| Base 13 | 3a613 | 41213 |
| Base 14 | 33d14 | 37514 |
| Base 15 | 2cd15 | 31115 |
| Base 16 | 28316 | 2b316 |