Compare 1961 vs 1981
| Property | 1961 | 1981 |
|---|---|---|
| Type | semiprime | semiprime |
| Unique factors | 2 | 2 |
| Total factors | 2 | 2 |
| Prime factorization | 371 × 531 | 71 × 2831 |
| Prime factorization | 37 × 53 | 7 × 283 |
| Divisors count | 4 | 4 |
| Divisors | 1, 37, 53, 1961 | 1, 7, 283, 1981 |
| Number of properties | 1 | 1 |
| Semiprimes | 566th | 572nd |
| Roman numberals | MCMLXI | MCMLXXXI |
| Base 2 | 111101010012 | 111101111012 |
| Base 3 | 22001223 | 22011013 |
| Base 4 | 1322214 | 1323314 |
| Base 5 | 303215 | 304115 |
| Base 6 | 130256 | 131016 |
| Base 7 | 55017 | 55307 |
| Base 8 | 36518 | 36758 |
| Base 9 | 26189 | 26419 |
| Base 10 | 196110 | 198110 |
| Base 11 | 152311 | 154111 |
| Base 12 | 117512 | 119112 |
| Base 13 | b7b13 | b9513 |
| Base 14 | a0114 | a1714 |
| Base 15 | 8ab15 | 8c115 |
| Base 16 | 7a916 | 7bd16 |