Compare 1991 vs 2005
| Property | 1991 | 2005 |
|---|---|---|
| Type | semiprime | semiprime |
| Unique factors | 2 | 2 |
| Total factors | 2 | 2 |
| Prime factorization | 111 × 1811 | 51 × 4011 |
| Prime factorization | 11 × 181 | 5 × 401 |
| Divisors count | 4 | 4 |
| Divisors | 1, 11, 181, 1991 | 1, 5, 401, 2005 |
| Number of properties | 1 | 1 |
| Semiprimes | 576th | 578th |
| Roman numberals | MCMXCI | MMV |
| Base 2 | 111110001112 | 111110101012 |
| Base 3 | 22012023 | 22020213 |
| Base 4 | 1330134 | 1331114 |
| Base 5 | 304315 | 310105 |
| Base 6 | 131156 | 131416 |
| Base 7 | 55437 | 55637 |
| Base 8 | 37078 | 37258 |
| Base 9 | 26529 | 26679 |
| Base 10 | 199110 | 200510 |
| Base 11 | 155011 | 156311 |
| Base 12 | 119b12 | 11b112 |
| Base 13 | ba213 | bb313 |
| Base 14 | a2314 | a3314 |
| Base 15 | 8cb15 | 8da15 |
| Base 16 | 7c716 | 7d516 |