Compare 1999 vs 2009
| Property | 1999 | 2009 |
|---|---|---|
| Type | prime | composite number |
| Unique factors | 1 | 2 |
| Total factors | 1 | 3 |
| Prime factorization | 19991 | 72 × 411 |
| Prime factorization | 1999 | 7 × 7 × 41 |
| Divisors count | 2 | 6 |
| Divisors | 1, 1999 | 1, 7, 41, 49, 287, 2009 |
| Number of properties | 8 | 0 |
| Centered triangular primes | 10th | |
| Cousin primes (1st member) | 65th | |
| Primes | 303rd | |
| Prime triplets (2nd member) | 50th | |
| Prime triplets (3rd member) | 49th | |
| Sexy primes (2nd member) | 128th | |
| Sexy prime triplets (3rd member) | 50th | |
| Twin primes (2nd member) | 61st | |
| Roman numberals | MCMXCIX | MMIX |
| Base 2 | 111110011112 | 111110110012 |
| Base 3 | 22020013 | 22021023 |
| Base 4 | 1330334 | 1331214 |
| Base 5 | 304445 | 310145 |
| Base 6 | 131316 | 131456 |
| Base 7 | 55547 | 56007 |
| Base 8 | 37178 | 37318 |
| Base 9 | 26619 | 26729 |
| Base 10 | 199910 | 200910 |
| Base 11 | 155811 | 156711 |
| Base 12 | 11a712 | 11b512 |
| Base 13 | baa13 | bb713 |
| Base 14 | a2b14 | a3714 |
| Base 15 | 8d415 | 8de15 |
| Base 16 | 7cf16 | 7d916 |