| ||||
|---|---|---|---|---|
| Cardinal | two hundred twenty-one | |||
| Ordinal | 221st (two hundred twenty-first) | |||
| Factorization | 13 × 17 | |||
| Greek numeral | ΣΚΑ´ | |||
| Roman numeral | CCXXI | |||
| Binary | 110111012 | |||
| Ternary | 220123 | |||
| Senary | 10056 | |||
| Octal | 3358 | |||
| Duodecimal | 16512 | |||
| Hexadecimal | DD16 | |||
221 (two hundred [and] twenty-one) is the natural number following 220 and preceding 222.