Eight

The eight (8) is the natural number that follows seven (7) and precedes nine (9).

An eight number made from led flashlights.

Math

• A composite number its own divisors are: 1, 2, 4, as the sum of its own divisors is: 7 ≤ 8 therefore is a defective number. The sum of its dividers 1, 2, 4, 8 = 15.
• The 8-sided polygon is named octagon. Figured numbers representing octagonals are called octagonal numbers.
• A cop with eight faces is an octahedron.
• 3.a power of two.
• 8² = 64.
• Double factorial of 4.
• It is the sixth term of Fibonacci succession, after 5 and before 13.
• It is a number of Leyland since 2² + 2² = 8.
• It's a perfect bucket (2³).
• The only positive power that is one less than another positive power according to Catalan conjecture.
• A pie number.
• The eight divisions of a three-dimensional Cartesian coordinate system are called an octator.
• The eight is the basis of the octal numbering system.
• E8, is a group of Lie (the largest) simple and exceptional.
• Number of symmetries of a square.
• A cube has eight vertices.
• There are eight convex deltaedros.
• Octonions have 8 dimensions.
• All sphenoid numbers have 8 divisors.
• The eight lying down symbolizes the infinite.
• A refactorable number.
• It's a practical number.

Volcanology

• The Volcanic Explosive Index IEV (originally in English, Volcanic Explosivity Index, VEI) is a scale of 8 degrees with which vulcanologists measure the magnitude of a volcanic eruption.

Chemistry

• It is the atomic number of oxygen (O).
• Atoms will always seek to have 8 electrons of valence to this is known as the Rule of the Octeto.
• It's eight planets in our solar system.

Physics

• 2.o magic number in physics.
• In the Anglo-Saxon measurement system, there are 8 liquid ounces in an American cup, 8 paints in a gallon and 8 furlongs in a mile.