Compare 391 vs 401
| Property | 391 | 401 |
|---|---|---|
| Type | semiprime | prime |
| Unique factors | 2 | 1 |
| Total factors | 2 | 1 |
| Prime factorization | 171 × 231 | 4011 |
| Prime factorization | 17 × 23 | 401 |
| Divisors count | 4 | 2 |
| Divisors | 1, 17, 23, 391 | 1, 401 |
| Number of properties | 1 | 7 |
| Additive primes | 46th | |
| Chen primes | 56th | |
| Cousin primes (2nd member) | 22nd | |
| Isolated primes | 38th | |
| Primes | 79th | |
| Pythagorean primes | 38th | |
| Semiprimes | 122nd | |
| Super primes | 22nd | |
| Roman numberals | CCCXCI | CDI |
| Base 2 | 1100001112 | 1100100012 |
| Base 3 | 1121113 | 1122123 |
| Base 4 | 120134 | 121014 |
| Base 5 | 30315 | 31015 |
| Base 6 | 14516 | 15056 |
| Base 7 | 10667 | 11127 |
| Base 8 | 6078 | 6218 |
| Base 9 | 4749 | 4859 |
| Base 10 | 39110 | 40110 |
| Base 11 | 32611 | 33511 |
| Base 12 | 28712 | 29512 |
| Base 13 | 24113 | 24b13 |
| Base 14 | 1dd14 | 20914 |
| Base 15 | 1b115 | 1bb15 |
| Base 16 | 18716 | 19116 |