Compare 21 vs 28
Property | 21 | 28 |
---|---|---|
Type | semiprime | composite number |
Unique factors | 2 | 2 |
Total factors | 2 | 3 |
Prime factorization | 31 × 71 | 22 × 71 |
Prime factorization | 3 × 7 | 2 × 2 × 7 |
Divisors count | 4 | 6 |
Divisors | 1, 3, 7, 21 | 1, 2, 4, 7, 14, 28 |
Number of properties | 1 | 0 |
Semiprimes | 7th | |
Roman numberals | XXI | XXVIII |
Base 2 | 101012 | 111002 |
Base 3 | 2103 | 10013 |
Base 4 | 1114 | 1304 |
Base 5 | 415 | 1035 |
Base 6 | 336 | 446 |
Base 7 | 307 | 407 |
Base 8 | 258 | 348 |
Base 9 | 239 | 319 |
Base 10 | 2110 | 2810 |
Base 11 | 1a11 | 2611 |
Base 12 | 1912 | 2412 |
Base 13 | 1813 | 2213 |
Base 14 | 1714 | 2014 |
Base 15 | 1615 | 1d15 |
Base 16 | 1516 | 1c16 |