The 255 (number) reference article from the English Wikipedia on 24-Apr-2004 (provided by Fixed Reference: snapshots of Wikipedia from wikipedia.org)

255 (number)

This article is about the number 255. For the year AD 255, see 255.

Two hundred fifty-five (255, CCLV) is the natural number following 254 and preceding 256. Its factorization is

making it a sphenic number.

The number is a special number in some tasks having to do with computing. This is the maximum value representable by an eight-digit binary number, and therefore the maximum representable by an unsigned 8-bit byte (the most common size of byte, also called octet), the smallest common variable size used in high level programming languages (bit being smaller, but rarely used for value storage). The range is 0 to 255, which is 256 total values.

Due to this, this number frequently occurs in video games when a small number is needed.

• There are exactly 255 levels in Pac-Man.
• In The Legend of Zelda, the maximum number of rupeess you may have at one time is 255.

Other common numbers include 127, 32767, 65535, 2147483647 and 4294967295 -- all of which are 2 raised to a power, minus 1. Representative of signed and unsigned 8-bit, 16-bit and 32-bit numbers. The popular Intel CPU's have had registers of these sizes.

In 2003 64-bit processors are gaining popularity so expect to see the numbers 18446744073709551615 and 9223372036854775807. 128 bit numbers are larger than can be typically displayed without using scientific notation. 2¹²⁷ (max value of a signed 128 bit number; in 1's or 2's complement notation, it may be 1 lower) is 1.7014118346046923173168730371588e+38 and 2¹²⁸ is 3.4028236692093846346337460743177e+38.

See also

• Integer
• List of numbers
• 200 (number)

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