75 (seventy-five) is the natural number following 74 and preceding 76.
75 | |
---|---|
Cardinal | seventy-five |
Ordinal | 75th (seventy-fifth) |
Numeral system | 75 |
Factorization | |
Divisors | 1, 3, 5, 15, 25, 75 |
Roman numeral | LXXV |
Binary | 10010112 |
Octal | 1138 |
Duodecimal | 6312 |
Hexadecimal | 4B16 |
As the sum of the first five pentagonal numbers, seventy-five is a pentagonal pyramidal number. It is also an enneagonal number.
It is also a Keith number, because it recurs in a Fibonacci-like sequence started from its base 10 digits: 7, 5, 12, 17, 29, 46, 75... But there is no integer that added up to its own digits adds up to 75, hence 75 is a self number.
Excluding the infinite sets, there are 75 uniform polyhedra (or 76 if edges are allowed to coincide).
Seventy-five is also: