Compare 191 vs 521
| Property | 191 | 521 |
|---|---|---|
| Type | prime | prime |
| Unique factors | 1 | 1 |
| Total factors | 1 | 1 |
| Prime factorization | 1911 | 5211 |
| Prime factorization | 191 | 521 |
| Divisors count | 2 | 2 |
| Divisors | 1, 191 | 1, 521 |
| Number of properties | 16 | 6 |
| Additive primes | 24th | |
| Chen primes | 34th | 70th |
| Class 1+ primes | 14th | |
| Good primes | 16th | |
| Harmonic primes | 15th | |
| Lucas primes | 8th | |
| Palindromic primes | 10th | |
| Pierpont primes of the 2nd kind | 14th | |
| Primes | 43rd | 98th |
| Prime quadruplets (1st member) | 4th | |
| Prime triplets (1st member) | 13th | |
| Pythagorean primes | 46th | |
| Sexy primes (1st member) | 25th | |
| Solinas primes | 25th | 39th |
| Sophie germain primes | 15th | |
| Super primes | 14th | |
| Thabit primes | 6th | |
| Twin primes (1st member) | 14th | 25th |
| Roman numberals | CXCI | DXXI |
| Base 2 | 101111112 | 10000010012 |
| Base 3 | 210023 | 2010223 |
| Base 4 | 23334 | 200214 |
| Base 5 | 12315 | 40415 |
| Base 6 | 5156 | 22256 |
| Base 7 | 3627 | 13437 |
| Base 8 | 2778 | 10118 |
| Base 9 | 2329 | 6389 |
| Base 10 | 19110 | 52110 |
| Base 11 | 16411 | 43411 |
| Base 12 | 13b12 | 37512 |
| Base 13 | 11913 | 31113 |
| Base 14 | d914 | 29314 |
| Base 15 | cb15 | 24b15 |
| Base 16 | bf16 | 20916 |