Twenty

Twenty (20) is the natural number following nineteen and preceding twenty-one.

Twenty is a composite number, its proper divisors being 1, 2, 4, 5 and 10.

Twenty is used as a base number for vigesimal number systems.

In the old UK currency system, there were twenty shillings in a pound.

A group of twenty is often referred to as a score.

A polyhedron with twenty faces is an icosahedron.