8 (eight) is the natural number following seven and preceding nine.
Mathematics
It is a composite number, its proper divisors being 1, 2, and 4.
Eight is a power of two, being 23, or two cubed.
8 is the base of the octal number system, which is mostly used with computers. In octal, one digit represents three bits.
The number 8 is a Fibonacci number, being 3 plus 5. The next Fibonacci number is 13.
In binary code eight is 1000; in ternary code eight is 22; in quaternary numeral system code eight is 20; in quinary eight is 13; in senary eight is 12; in septenary eight is 11; in octal eight is 10; in novenary code and all codes above (such as decimal and hexadecimal) eight is 8. In Roman numerals eight is VIII.
A polygon with eight sides is an octagon.
A polyhedron with eight faces is an octahedron.
Other fields
- Eight (八 pinyin ba1) is considered a lucky number in Chinese culture because it sounds like the word "prosper" (發 pinyin fa1).
- There are eight musicians in an octet.
- Eight babies delivered in one birth are called octuplets. The first set of eight surviving babies, the Louis-Chukwu Octuplets, were born in 1998. On The Simpsons, Apu and his wife Manjula have a set of octuplets.
- All spiders, and more generally all arachnids, have eight legs. An octopus has eight tentacles.
- In Buddhism, the Eightfold Path is the way to spiritual progress.
- Timothy Leary identified a hierarchy of eight levels of consciousness.
- October was the eighth month in the Roman calendar, August is currently the eighth month.
- Eight cannot be said by a wizard on the Discworld and is also the number of Bel-Shamharoth.
- Referring to the shape of the numeral, eight was represented in bingo slang, before political correctness, as 'One Fat Lady.' Eighty-eight was 'Two Fat Ladies'.
- Eight ball billiards is played with 15 balls; the black ball numbered 8 is the most important one. Eight-balls are often sold as fortune-telling devices.
- "Eight maids a-milking" is the gift on the eighth day of Christmas in the "Twelve days of Christmas" carol.
- There are eight categories of political ideology on a Vosem Chart, which gets its name from восемь, the Russian word for eight, or on a Friesian Cube (see political spectrum). Eight is also the number of categories the VALS system uses to classify consumer groups, and the number of categories used by Fallon-McElligott's system for teen marketing.
- There is a brand of chocolate called "After Eight", referring to the time 8 p.m.
- There are eight vegetables in V8 juice.
- The number on Walt Disney's Herbie adds up to eight.
- Using hyperbole, the Beatles sang about loving their addressee "Eight Days a Week". Also from music is the 8-track.
- A note played for one-eighth the duration of a whole note is called an eight note, or quaver.
- The numeral "8" is sometimes used in writing to represent the syllable "ate", as in writing "H8" for "hate", or "congratul8ons" for "congratulations". Avril Lavigne's song "Sk8er Boi" uses this convention in the title.
- Several groups of "Eight Immortals"
- Eight Principles of Yong
- War of the Eight Princes
- Eight queens puzzle
- The year AD 8.
