Names of 665
| Nominal | 665 |
| Cardinal | six hundred sixty-five |
| Ordinal | 665th |
| This number as US currency | six hundred sixty-five dollars |
| Is 665 an odd number? | 665 is an odd number |
| Is 665 an even number? | 665 is NOT an even number |
| Is 665 a palindrome? | 665 is NOT a palindrome number |
| Is 665 a triangle number? | 665 is NOT a triangle number |
665 in other Bases
| Base 2 (Binary) | 10100110012 |
| Base 3 (Ternary) | 2201223 |
| Base 4 (Quaternary) | 221214 |
| Base 5 (Quinary) | 101305 |
| Base 6 (Senary) | 30256 |
| Base 8 (Octal) | 12318 |
| Base 12 (Duodecimal) | 47512 |
| Base 16 (Hexadecimal) | 29916 |
| Base 20 (Vigesimal) | 1D520 |
Primes and Factors tests for 665
| Is 665 a Prime Number? | 665 is NOT a prime |
| Is 665 a perfect number? | 665 is NOT a perfect number |
| Is 665 a Mersenne Prime? | 665 is NOT a Mersenne prime |
| Is 665 a Fermat Prime? | 665 is NOT a Fermat prime |
| Is 665 a Fibonacci Prime? | 665 is NOT a Fibonacci prime |
| Is 665 a Partition Prime? | 665 is NOT a Partition prime |
| Is 665 a Pell Prime? | 665 is NOT a Pell prime |
| Prime Factors | Prime factors of 665 |
Sponsored
665 in other Numerals
| 665 in Roman Numeral | DCLXV |
| 665 in Chinese Numeral | 陸佰陸拾伍 |
| 665 in Egyptian Numeral | 𓍧𓎋𓏾 |
| 665 in Babylonian Numeral |   |
Roots and stuff for 665
| Is 665 a square number? | 665 is NOT a square number |
| Is 665 a cube number? | 665 is NOT a cube number |
| Square root of the number 665 | 25.787593916455 |
| Cube root of the number 665 | 8.728518735186 |
Recreational math for 665
| Number 665 reversed | 566 |
| Sum of the digits | 17 |
| No of digits | 3 |