Compare 991 vs 1031
| Property | 991 | 1031 |
|---|---|---|
| Type | prime | prime |
| Unique factors | 1 | 1 |
| Total factors | 1 | 1 |
| Prime factorization | 9911 | 10311 |
| Prime factorization | 991 | 1031 |
| Divisors count | 2 | 2 |
| Divisors | 1, 991 | 1, 1031 |
| Number of properties | 10 | 9 |
| Additive primes | 89th | 92nd |
| Chen primes | 115th | 118th |
| Emirps | 36th | 39th |
| Good primes | 46th | |
| Isolated primes | 98th | |
| Lucky primes | 42nd | |
| Primes | 167th | 173rd |
| Sexy primes (1st member) | 74th | |
| Solinas primes | 43rd | 47th |
| Sophie germain primes | 40th | |
| Super primes | 39th | 40th |
| Twin primes (1st member) | 37th | |
| Ulam primes | 18th | |
| Roman numberals | CMXCI | MXXXI |
| Base 2 | 11110111112 | 100000001112 |
| Base 3 | 11002013 | 11020123 |
| Base 4 | 331334 | 1000134 |
| Base 5 | 124315 | 131115 |
| Base 6 | 43316 | 44356 |
| Base 7 | 26147 | 30027 |
| Base 8 | 17378 | 20078 |
| Base 9 | 13219 | 13659 |
| Base 10 | 99110 | 103110 |
| Base 11 | 82111 | 85811 |
| Base 12 | 6a712 | 71b12 |
| Base 13 | 5b313 | 61413 |
| Base 14 | 50b14 | 53914 |
| Base 15 | 46115 | 48b15 |
| Base 16 | 3df16 | 40716 |