Compare 1987 vs 1991
| Property | 1987 | 1991 |
|---|---|---|
| Type | prime | semiprime |
| Unique factors | 1 | 2 |
| Total factors | 1 | 2 |
| Prime factorization | 19871 | 111 × 1811 |
| Prime factorization | 1987 | 11 × 181 |
| Divisors count | 2 | 4 |
| Divisors | 1, 1987 | 1, 11, 181, 1991 |
| Number of properties | 6 | 1 |
| Good primes | 62nd | |
| Isolated primes | 181st | |
| Lucky primes | 70th | |
| Primes | 300th | |
| Semiprimes | 576th | |
| Sexy primes (1st member) | 127th | |
| Sexy prime triplets (1st member) | 50th | |
| Roman numberals | MCMLXXXVII | MCMXCI |
| Base 2 | 111110000112 | 111110001112 |
| Base 3 | 22011213 | 22012023 |
| Base 4 | 1330034 | 1330134 |
| Base 5 | 304225 | 304315 |
| Base 6 | 131116 | 131156 |
| Base 7 | 55367 | 55437 |
| Base 8 | 37038 | 37078 |
| Base 9 | 26479 | 26529 |
| Base 10 | 198710 | 199110 |
| Base 11 | 154711 | 155011 |
| Base 12 | 119712 | 119b12 |
| Base 13 | b9b13 | ba213 |
| Base 14 | a1d14 | a2314 |
| Base 15 | 8c715 | 8cb15 |
| Base 16 | 7c316 | 7c716 |