Twenty or 20 is the natural number that follows 19 and precedes 21. A set of twenty units is usually called as a score.

The number twenty is a composite number, as its proper divisors are 1, 2, 4, 5, and 10. By omitting two and totalling up the other divisors gives the sum of twenty, thus twenty is a semi perfect type of number. Since it cannot be divided by any of the lesser semi perfect numbers, it is also a primitive semi perfect number. Twenty is also the smallest abundant number that is not a manifold of the number three.

It is also a tetrahedral number, as it is the sum of the first four triangular numbers.

Interestingly, twenty is the number of all the digits in the body put together, and that makes it a potential contender for a numeral arrangement.

The number twenty is a composite number, as its proper divisors are 1, 2, 4, 5, and 10. By omitting two and totalling up the other divisors gives the sum of twenty, thus twenty is a semi perfect type of number. Since it cannot be divided by any of the lesser semi perfect numbers, it is also a primitive semi perfect number. Twenty is also the smallest abundant number that is not a manifold of the number three.

It is also a tetrahedral number, as it is the sum of the first four triangular numbers.

Interestingly, twenty is the number of all the digits in the body put together, and that makes it a potential contender for a numeral arrangement.