Compare 1991 vs 2026
| Property | 1991 | 2026 |
|---|---|---|
| Type | semiprime | semiprime |
| Unique factors | 2 | 2 |
| Total factors | 2 | 2 |
| Prime factorization | 111 × 1811 | 21 × 10131 |
| Prime factorization | 11 × 181 | 2 × 1013 |
| Divisors count | 4 | 4 |
| Divisors | 1, 11, 181, 1991 | 1, 2, 1013, 2026 |
| Number of properties | 1 | 1 |
| Semiprimes | 576th | 582nd |
| Roman numberals | MCMXCI | MMXXVI |
| Base 2 | 111110001112 | 111111010102 |
| Base 3 | 22012023 | 22100013 |
| Base 4 | 1330134 | 1332224 |
| Base 5 | 304315 | 311015 |
| Base 6 | 131156 | 132146 |
| Base 7 | 55437 | 56237 |
| Base 8 | 37078 | 37528 |
| Base 9 | 26529 | 27019 |
| Base 10 | 199110 | 202610 |
| Base 11 | 155011 | 158211 |
| Base 12 | 119b12 | 120a12 |
| Base 13 | ba213 | bcb13 |
| Base 14 | a2314 | a4a14 |
| Base 15 | 8cb15 | 90115 |
| Base 16 | 7c716 | 7ea16 |