256 (number)

← 255 256 257 →
← 250 251 252 253 254 255 256 257 258 259 → List of numbers Integers ← 0 100 200 300 400 500 600 700 800 900 →
Cardinal	two hundred fifty-six
Ordinal	256th (two hundred fifty-sixth)
Factorization	28
Greek numeral	ΣΝϚ´
Roman numeral	CCLVI
Binary	1000000002
Ternary	1001113
Senary	11046
Octal	4008
Duodecimal	19412
Hexadecimal	10016

256 (two hundred [and] fifty-six) is the natural number following 255 and preceding 257.

In mathematics

256 is a composite number, with the factorization 256 = 2⁸, which makes it a power of two.

• 256 is 4 raised to the 4th power, so in tetration notation, 256 is ²4.
  • 256 is the value of the expression $n^{n}$, where $n=4$.
• 256 is a perfect square (16²).
• 256 is the only 3-digit number that is zenzizenzizenzic. It is 2 to the 8th power or $((2^{2})^{2})^{2}$.
• 256 is the lowest number that is a product of eight prime factors.
• 256 is the number of parts in all compositions of 7.

In computing

One octet (in most cases one byte) is equal to eight bits and has 2⁸ or 256 possible values, counting from 0 to 255. The number 256 often appears in computer applications (especially on 8-bit systems) such as:

• The typical number of different values in each color channel of a digital color image (256 values for red, 256 values for green, and 256 values for blue used for 24-bit color) (see color space or Web colors).
• The number of colors available in a GIF or a 256-color (8-bit) bitmap.
• The number of characters in extended ASCII and Latin-1.
• The number of columns available in a Microsoft Excel worksheet until Excel 2007.
• The split-screen level in Pac-Man, which results from the use of a single byte to store the internal level counter.
• A 256-bit unsigned integer can represent up to 115,792,089,237,316,195,423,570,985,008,687,907,853,269,984,665,640,564,039,457,584,007,913,129,639,936 values.
• The number of bits in the SHA-256 cryptographic hash.
• The branding number of Nvidia's GeForce 256.