48 (number)
48 is the natural number following 47 and preceding 49.
| Template:Numbers 40s | |
| Cardinal | forty-eight |
| Ordinal | 48th (forty-eighth) |
| Factorization | |
| Divisors | 2, 3, 4, 6, 8, 12, 16, 24 |
| Roman numeral | XLVIII |
| Binary | 0110000 |
| Hexadecimal | 30 |
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 other fields
Forty-eight is also:
- the atomic number of cadmium.
- 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 number of constellations counted by Ptolemy.
- 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.