48 is the natural number following 47 and preceding 49.
In mathematics
Forty-eight is the double factorial of 6, four dozens, a highly composite number, a 17-gonal number and a Harshad number.
There are 11 solutions to the equation φ(x) = 48, namely 65, 104, 105, 112, 130, 140, 144, 156, 168, 180 and 210. This is more than any integer below 48, making 48 a highly totient number.
In science
In astronomy,
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Messier object M48, a magnitude 5.5 open cluster in the constellation Hydra
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The New General Catalogue object NGC 48 , a barred spiral galaxy in the constellation Andromeda
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The Saros number of the solar eclipse series which began on -1331 February 8 and ended on -15 April 9. The duration of Saros series 48 was 1316.2 years, and it contained 74 solar eclipses.
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The Saros number of the lunar eclipse series which began on -1246 July 11 and ended on 124 October 11. The duration of Saros series 48 was 1370.3 years, and it contained 77 lunar eclipses.
In other fields
Forty-eight is also:
- twice the total number of major and minor keys in the Western tonal music (twenty-four), not counting enharmonic equivalents. Johann Sebastian Bach's Well-Tempered Clavier is informally known as The Forty-Eight because it consists of a prelude and a fugue in each major and minor key, for a total of forty-eight pieces.
- the code for international direct dial phone calls to Poland.
- the model number of the HP-48 S/SX/G/GX/G+/GII
- the number of hours in two days, and hence also part of the title of the movies 48 Hrs. and Another 48 Hrs., starring Eddie Murphy and Nick Nolte.
- the years AD 48, 48 BC, or 1948.
Last updated: 05-24-2005 11:13:22