Compare 1999 vs 2005
| Property | 1999 | 2005 |
|---|---|---|
| Type | prime | semiprime |
| Unique factors | 1 | 2 |
| Total factors | 1 | 2 |
| Prime factorization | 19991 | 51 × 4011 |
| Prime factorization | 1999 | 5 × 401 |
| Divisors count | 2 | 4 |
| Divisors | 1, 1999 | 1, 5, 401, 2005 |
| Number of properties | 8 | 1 |
| Centered triangular primes | 10th | |
| Cousin primes (1st member) | 65th | |
| Primes | 303rd | |
| Prime triplets (2nd member) | 50th | |
| Prime triplets (3rd member) | 49th | |
| Semiprimes | 578th | |
| Sexy primes (2nd member) | 128th | |
| Sexy prime triplets (3rd member) | 50th | |
| Twin primes (2nd member) | 61st | |
| Roman numberals | MCMXCIX | MMV |
| Base 2 | 111110011112 | 111110101012 |
| Base 3 | 22020013 | 22020213 |
| Base 4 | 1330334 | 1331114 |
| Base 5 | 304445 | 310105 |
| Base 6 | 131316 | 131416 |
| Base 7 | 55547 | 55637 |
| Base 8 | 37178 | 37258 |
| Base 9 | 26619 | 26679 |
| Base 10 | 199910 | 200510 |
| Base 11 | 155811 | 156311 |
| Base 12 | 11a712 | 11b112 |
| Base 13 | baa13 | bb313 |
| Base 14 | a2b14 | a3314 |
| Base 15 | 8d415 | 8da15 |
| Base 16 | 7cf16 | 7d516 |