8  

Cardinal  8 eight 
Ordinal  8th eighth 
Numeral system  octal 
Factorization  2^{3} 
Divisors  1, 2, 4, 8 
Roman numeral  VIII 
Roman numeral (Unicode)  Ⅷ, ⅷ 
Arabic  ٨,8 
Amharic  ፰ 
Bengali  ৮ 
Chinese numeral  八，捌 
Devanāgarī  ८ 
Tamil  ௮ 
Hebrew  ח (Het) 
Hebrew  שמונה (shmoneh) 
Khmer  ៨ 
Korean  팔 
Thai  ๘ 
prefixes  octa/oct (from Greek) 
Binary  1000 
Octal  10 
Duodecimal  8 
Hexadecimal  8 
8 (eight) is the natural number following 7 and preceding 9. The SI prefix for 1000^{8} is yotta (Y), and for its reciprocal yocto (y). It is the root of two other numbers: eighteen (eight and ten) and eighty (eight tens). Linguistically, it is derived from Middle English eighte.^{[citation needed]}
Contents 
8 is a composite number, its proper divisors being 1, 2, and 4. It is twice 4 or four times 2. Eight is a power of two, being 2^{3} (two cubed), and is the first number of the form p^{3}. It has an aliquot sum of 7 in the 4 member aliquot sequence (8,7,1,0) being the first member of 7aliquot tree. It is symbolized by the Arabic numeral (figure) 8.
All powers of 2 ;(2^{x}), have an aliquot sum of one less than themselves.
Eight is the first number to be the aliquot sum of two numbers other than itself; the discrete biprime 10, and the square number 49.
8 is the base of the octal number system, which is mostly used with computers. In octal, one digit represents 3 bits. In modern computers, a byte is a grouping of eight bits, also called an octet.
The number 8 is a Fibonacci number, being 3 plus 5. The next Fibonacci number is 13. 8 is the only positive Fibonacci number, aside from 1, that is a perfect cube.^{[1]}
8 and 9 form a Ruth–Aaron pair under the second definition in which repeated prime factors are counted as often as they occur.
A polygon with eight sides is an octagon. Figurate numbers representing octagons (including eight) are called octagonal numbers. A polyhedron with eight faces is an octahedron. A cuboctahedron has as faces six equal squares and eight equal regular triangles.
Sphenic numbers always have exactly eight divisors.
8 is the dimension of the octonions and is the highest possible dimension of a normed division algebra.
The number 8 is involved with a number of interesting mathematical phenomena related to the notion of Bott periodicity. For example if is the direct limit of the inclusions of real orthogonal groups then . Clifford algebras also display a periodicity of 8. For example the algebra Cl(p + 8,q) is isomorphic to the algebra of 16 by 16 matrices with entries in Cl(p,q). We also see a period of 8 in the Ktheory of spheres and in the representation theory of the rotation groups, the latter giving rise to the 8 by 8 spinorial chessboard. All of these properties are closely related to the properties of the octonions.
The lowest dimensional even unimodular lattice is the 8dimensional E_{8} lattice. Even positive definite unimodular lattice exist only in dimensions divisible by 8.
A figure 8 is the common name of a geometric shape, often used in the context of sports, such as skating. Figureeight turns of a rope or cable around a cleat, pin, or bitt are used to belay something.
Base  Numeral system  

2  binary  1000 (number) 
3  ternary  22 (number) 
4  quaternary  20 (number) 
5  quinary  13 (number) 
6  senary  12 (number) 
7  septenary  11 (number) 
8  octal  10 (number) 
over 8 (decimal, hexadecimal)  8 (number) 
The figure eight is a popular move in ice skating.
In the beginning, various groups in India wrote eight more or less in one stroke as a curve that looks like an uppercase H with the bottom half of the left line and the upper half of the right line removed. At one point this glyph came close to looking like our modern five. With the western Ghubar Arabs, the similarity of the glyph to five was banished by connecting the beginning and the end of stroke together, and it was only a matter of the Europeans rounding the glyph that led to our modern eight.^{[2]}
Just as in most modern typefaces, in typefaces with text figures the 8 character usually has an ascender, as, for example, in . The "1" and "4" are oldstyle figures; the "8" is the same height in both oldstyle and modern figures. 1234567890 are all the same height; they are modern figures.
The number eight is a natural number that comes after the number seven, but before the number nine.
In math, the number eight is an even number and a composite number. Eight is also a power of two, being 2 times itself 3 times.koi:8 (кыкьямыс)
