Forty-eight (48, XLVIII) is the natural number following forty-seven and preceeding forty-nine. Constituted of four dozens, its divisors are 1, 2, 3, 4, 6, 8, 12, 16, 24, and 48, making it a highly composite number; its factorisation is

• 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 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 code for international direct dial phone calls to Poland.