Compare 249 vs 251
| Property | 249 | 251 |
|---|---|---|
| Type | semiprime | prime |
| Unique factors | 2 | 1 |
| Total factors | 2 | 1 |
| Prime factorization | 31 × 831 | 2511 |
| Prime factorization | 3 × 83 | 251 |
| Divisors count | 4 | 2 |
| Divisors | 1, 3, 83, 249 | 1, 251 |
| Number of properties | 1 | 10 |
| Chen primes | 41st | |
| Good primes | 19th | |
| Harmonic primes | 20th | |
| Isolated primes | 21st | |
| Primes | 54th | |
| Semiprimes | 80th | |
| Sexy primes (1st member) | 30th | |
| Sexy prime quadrupletss (1st member) | 5th | |
| Sexy prime triplets (1st member) | 15th | |
| Solinas primes | 30th | |
| Sophie germain primes | 18th | |
| Roman numberals | CCXLIX | CCLI |
| Base 2 | 111110012 | 111110112 |
| Base 3 | 1000203 | 1000223 |
| Base 4 | 33214 | 33234 |
| Base 5 | 14445 | 20015 |
| Base 6 | 10536 | 10556 |
| Base 7 | 5047 | 5067 |
| Base 8 | 3718 | 3738 |
| Base 9 | 3069 | 3089 |
| Base 10 | 24910 | 25110 |
| Base 11 | 20711 | 20911 |
| Base 12 | 18912 | 18b12 |
| Base 13 | 16213 | 16413 |
| Base 14 | 13b14 | 13d14 |
| Base 15 | 11915 | 11b15 |
| Base 16 | f916 | fb16 |