Compare 181 vs 185
| Property | 181 | 185 |
|---|---|---|
| Type | prime | semiprime |
| Unique factors | 1 | 2 |
| Total factors | 1 | 2 |
| Prime factorization | 1811 | 51 × 371 |
| Prime factorization | 181 | 5 × 37 |
| Divisors count | 2 | 4 |
| Divisors | 1, 181 | 1, 5, 37, 185 |
| Number of properties | 8 | 1 |
| Centered square primes | 6th | |
| Chen primes | 33rd | |
| Dihedral primes | 5th | |
| Long primes | 16th | |
| Palindromic primes | 9th | |
| Primes | 42nd | |
| Pythagorean primes | 19th | |
| Semiprimes | 60th | |
| Twin primes (2nd member) | 13th | |
| Roman numberals | CLXXXI | CLXXXV |
| Base 2 | 101101012 | 101110012 |
| Base 3 | 202013 | 202123 |
| Base 4 | 23114 | 23214 |
| Base 5 | 12115 | 12205 |
| Base 6 | 5016 | 5056 |
| Base 7 | 3467 | 3537 |
| Base 8 | 2658 | 2718 |
| Base 9 | 2219 | 2259 |
| Base 10 | 18110 | 18510 |
| Base 11 | 15511 | 15911 |
| Base 12 | 13112 | 13512 |
| Base 13 | 10c13 | 11313 |
| Base 14 | cd14 | d314 |
| Base 15 | c115 | c515 |
| Base 16 | b516 | b916 |