Compare 987 vs 991
| Property | 987 | 991 |
|---|---|---|
| Type | composite number | prime |
| Unique factors | 3 | 1 |
| Total factors | 3 | 1 |
| Prime factorization | 31 × 71 × 471 | 9911 |
| Prime factorization | 3 × 7 × 47 | 991 |
| Divisors count | 8 | 2 |
| Divisors | 1, 3, 7, 21, 47, 141, 329, 987 | 1, 991 |
| Number of properties | 0 | 10 |
| Additive primes | 89th | |
| Chen primes | 115th | |
| Emirps | 36th | |
| Isolated primes | 98th | |
| Lucky primes | 42nd | |
| Primes | 167th | |
| Sexy primes (1st member) | 74th | |
| Solinas primes | 43rd | |
| Super primes | 39th | |
| Ulam primes | 18th | |
| Roman numberals | CMLXXXVII | CMXCI |
| Base 2 | 11110110112 | 11110111112 |
| Base 3 | 11001203 | 11002013 |
| Base 4 | 331234 | 331334 |
| Base 5 | 124225 | 124315 |
| Base 6 | 43236 | 43316 |
| Base 7 | 26107 | 26147 |
| Base 8 | 17338 | 17378 |
| Base 9 | 13169 | 13219 |
| Base 10 | 98710 | 99110 |
| Base 11 | 81811 | 82111 |
| Base 12 | 6a312 | 6a712 |
| Base 13 | 5ac13 | 5b313 |
| Base 14 | 50714 | 50b14 |
| Base 15 | 45c15 | 46115 |
| Base 16 | 3db16 | 3df16 |