Compare 1820 vs 1821
| Property | 1820 | 1821 |
|---|---|---|
| Type | composite number | semiprime |
| Unique factors | 4 | 2 |
| Total factors | 5 | 2 |
| Prime factorization | 22 × 51 × 71 × 131 | 31 × 6071 |
| Prime factorization | 2 × 2 × 5 × 7 × 13 | 3 × 607 |
| Divisors count | 24 | 4 |
| Divisors | 1, 2, 4, 5, 7, 10, 13, 14, 20, 26, 28, 35, 52, 65, 70, 91, 130, 140, 182, 260, 364, 455, 910, 1820 | 1, 3, 607, 1821 |
| Number of properties | 0 | 1 |
| Semiprimes | 524th | |
| Roman numberals | MDCCCXX | MDCCCXXI |
| Base 2 | 111000111002 | 111000111012 |
| Base 3 | 21111023 | 21111103 |
| Base 4 | 1301304 | 1301314 |
| Base 5 | 242405 | 242415 |
| Base 6 | 122326 | 122336 |
| Base 7 | 52107 | 52117 |
| Base 8 | 34348 | 34358 |
| Base 9 | 24429 | 24439 |
| Base 10 | 182010 | 182110 |
| Base 11 | 140511 | 140611 |
| Base 12 | 107812 | 107912 |
| Base 13 | aa013 | aa113 |
| Base 14 | 94014 | 94114 |
| Base 15 | 81515 | 81615 |
| Base 16 | 71c16 | 71d16 |