Compare 1991 vs 2001
| Property | 1991 | 2001 |
|---|---|---|
| Type | semiprime | composite number |
| Unique factors | 2 | 3 |
| Total factors | 2 | 3 |
| Prime factorization | 111 × 1811 | 31 × 231 × 291 |
| Prime factorization | 11 × 181 | 3 × 23 × 29 |
| Divisors count | 4 | 8 |
| Divisors | 1, 11, 181, 1991 | 1, 3, 23, 29, 69, 87, 667, 2001 |
| Number of properties | 1 | 0 |
| Semiprimes | 576th | |
| Roman numberals | MCMXCI | MMI |
| Base 2 | 111110001112 | 111110100012 |
| Base 3 | 22012023 | 22020103 |
| Base 4 | 1330134 | 1331014 |
| Base 5 | 304315 | 310015 |
| Base 6 | 131156 | 131336 |
| Base 7 | 55437 | 55567 |
| Base 8 | 37078 | 37218 |
| Base 9 | 26529 | 26639 |
| Base 10 | 199110 | 200110 |
| Base 11 | 155011 | 155a11 |
| Base 12 | 119b12 | 11a912 |
| Base 13 | ba213 | bac13 |
| Base 14 | a2314 | a2d14 |
| Base 15 | 8cb15 | 8d615 |
| Base 16 | 7c716 | 7d116 |