Compare 991 vs 991
| Property | 991 | 991 |
|---|---|---|
| Type | prime | prime |
| Unique factors | 1 | 1 |
| Total factors | 1 | 1 |
| Prime factorization | 9911 | 9911 |
| Prime factorization | 991 | 991 |
| Divisors count | 2 | 2 |
| Divisors | 1, 991 | 1, 991 |
| Number of properties | 10 | 10 |
| Additive primes | 89th | 89th |
| Chen primes | 115th | 115th |
| Emirps | 36th | 36th |
| Isolated primes | 98th | 98th |
| Lucky primes | 42nd | 42nd |
| Primes | 167th | 167th |
| Sexy primes (1st member) | 74th | 74th |
| Solinas primes | 43rd | 43rd |
| Super primes | 39th | 39th |
| Ulam primes | 18th | 18th |
| Roman numberals | CMXCI | CMXCI |
| Base 2 | 11110111112 | 11110111112 |
| Base 3 | 11002013 | 11002013 |
| Base 4 | 331334 | 331334 |
| Base 5 | 124315 | 124315 |
| Base 6 | 43316 | 43316 |
| Base 7 | 26147 | 26147 |
| Base 8 | 17378 | 17378 |
| Base 9 | 13219 | 13219 |
| Base 10 | 99110 | 99110 |
| Base 11 | 82111 | 82111 |
| Base 12 | 6a712 | 6a712 |
| Base 13 | 5b313 | 5b313 |
| Base 14 | 50b14 | 50b14 |
| Base 15 | 46115 | 46115 |
| Base 16 | 3df16 | 3df16 |