Compare 1991 vs 2031
| Property | 1991 | 2031 |
|---|---|---|
| Type | semiprime | semiprime |
| Unique factors | 2 | 2 |
| Total factors | 2 | 2 |
| Prime factorization | 111 × 1811 | 31 × 6771 |
| Prime factorization | 11 × 181 | 3 × 677 |
| Divisors count | 4 | 4 |
| Divisors | 1, 11, 181, 1991 | 1, 3, 677, 2031 |
| Number of properties | 1 | 1 |
| Semiprimes | 576th | 583rd |
| Roman numberals | MCMXCI | MMXXXI |
| Base 2 | 111110001112 | 111111011112 |
| Base 3 | 22012023 | 22100203 |
| Base 4 | 1330134 | 1332334 |
| Base 5 | 304315 | 311115 |
| Base 6 | 131156 | 132236 |
| Base 7 | 55437 | 56317 |
| Base 8 | 37078 | 37578 |
| Base 9 | 26529 | 27069 |
| Base 10 | 199110 | 203110 |
| Base 11 | 155011 | 158711 |
| Base 12 | 119b12 | 121312 |
| Base 13 | ba213 | c0313 |
| Base 14 | a2314 | a5114 |
| Base 15 | 8cb15 | 90615 |
| Base 16 | 7c716 | 7ef16 |