75 (number)

From Wikipedia, the free encyclopedia

75 (seventy-five) is the natural number following 74 and preceding 76.

← 70 71 72 73 74 75 76 77 78 79 → List of numbers — Integers 0 10 20 30 40 50 60 70 80 90 →
Cardinal	75 seventy-five
Ordinal	75th seventy-fifth
Factorization	$3 \cdot 5^2$
Divisors	1, 3, 5, 15, 25, 75
Roman numeral	LXXV
Binary	1001011
Hexadecimal	4B

1 In mathematics
2 In astronomy
3 In geography
4 In other fields
5 In sports

[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 geography

The first two digits of the postal code for Paris

[edit] In other fields

Seventy-five is also:

Diamond anniversary
The atomic number of rhenium
The age limit for Canadian senators
A car model name used by the MG Rover Group, called the Rover 75
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
A common speed limit, in terms of miles per hour, in the western United States
A common name used for the Canon de 75 modèle 1897, a famous French artillery piece used throughout World War I
Sweet 75, a band, and self-titled CD
Peter, Paul, and Mary song "75 Septembers" on their LifeLines CD
Relient K song "High of 75" on their MMHMM CD
75, a song by Big Sur
Airport 1975 movie
Jackie Gleason in 1985 found 75 "lost" episodes of "The Honeymooners" (from 1952 and 1955)
Cheeta the chimpanzee of "Tarzan the Ape Man" is the world's oldest primate at 75 in 2007
Halley's Comet seen every 75-76 years
TV's Jetsons was a total 75 episodes in 3 seasons
CZ 75, the Czech pistol.
The number of counties in the USA state of Arkansas.