75 (number)
From Wikipedia, the free encyclopedia
75 (seventy-five) is the natural number following 74 and preceding 76.
| Cardinal | 75 seventy-five |
| Ordinal | 75th seventy-fifth |
| Factorization |  |
| Divisors | 1, 3, 5, 15, 25, 75 |
| Roman numeral | LXXV |
| Binary | 1001011 |
| Hexadecimal | 4B |
[edit] In mathematics
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.
There are 75 uniform polyhedra.
[edit] In astronomy
Messier object M75, a magnitude 9.5 globular cluster in the constellation Sagittarius
The New General Catalogue object NGC 75, a spiral galaxy in the constellation Pisces
[edit] In other fields
Seventy-five is also:
- The atomic number of rhenium
- The age limit for Canadian senators
- The designation of Interstate 75, a freeway that runs from Florida to Michigan.
- The registry of the U.S. Navy's nuclear aircraft carrier USS Harry S. Truman (CVN-75), named after U.S. President Harry S. Truman.
- The record for most game show wins, held by Ian Lygo. Also, the record for most game show appearances, currently a tie between Lygo and Ken Jennings.
- The year AD 75, 75 BC, or 1975.
- A common speed limit, in terms of miles per hour, in the western United States.
- Sweet 75, a band.
- The beginning of all 5 digit Paris Postal Codes (Not suburbs).
