Compare 1966 vs 1973
| Property | 1966 | 1973 | 
|---|---|---|
| Type | semiprime | prime | 
| Unique factors | 2 | 1 | 
| Total factors | 2 | 1 | 
| Prime factorization | 21 × 9831 | 19731 | 
| Prime factorization | 2 × 983 | 1973 | 
| Divisors count | 4 | 2 | 
| Divisors | 1, 2, 983, 1966 | 1, 1973 | 
| Number of properties | 1 | 7 | 
| Good primes | 61st | |
| Harmonic primes | 111th | |
| Isolated primes | 179th | |
| Primes | 298th | |
| Pythagorean primes | 145th | |
| Semiprimes | 568th | |
| Sexy primes (1st member) | 126th | |
| Sophie germain primes | 60th | |
| Roman numberals | MCMLXVI | MCMLXXIII | 
| Base 2 | 111101011102 | 111101101012 | 
| Base 3 | 22002113 | 22010023 | 
| Base 4 | 1322324 | 1323114 | 
| Base 5 | 303315 | 303435 | 
| Base 6 | 130346 | 130456 | 
| Base 7 | 55067 | 55167 | 
| Base 8 | 36568 | 36658 | 
| Base 9 | 26249 | 26329 | 
| Base 10 | 196610 | 197310 | 
| Base 11 | 152811 | 153411 | 
| Base 12 | 117a12 | 118512 | 
| Base 13 | b8313 | b8a13 | 
| Base 14 | a0614 | a0d14 | 
| Base 15 | 8b115 | 8b815 | 
| Base 16 | 7ae16 | 7b516 |