217 (number)
| ||||
|---|---|---|---|---|
| Cardinal | two hundred seventeen | |||
| Ordinal | 217th (two hundred seventeenth) | |||
| Factorization | 7 × 31 | |||
| Greek numeral | ΣΙΖ´ | |||
| Roman numeral | CCXVII | |||
| Binary | 110110012 | |||
| Ternary | 220013 | |||
| Senary | 10016 | |||
| Octal | 3318 | |||
| Duodecimal | 16112 | |||
| Hexadecimal | D916 | |||
217 (two hundred [and] seventeen) is the natural number following 216 and preceding 218.
In mathematics
217 is a centered hexagonal number, a 12-gonal number, a centered 36-gonal number, a Fermat pseudoprime to base 5, and a Blum integer.[1] It is both the sum of two positive cubes and the difference of two positive consecutive cubes in exactly one way: . When written in binary, it is a non-repetitive Kaprekar number.[2] It is also the sum of all the divisors of 100.
See also
- 217, the year
References
- ^ The Number 217, Virtue Science
- ^ The non-repetitive Kaprekar binary numbers in decimal, OEIS