(90, XC) is the natural number
preceded by eighty-nine
and followed by ninety-one
. It is the sums of the squares of the integers
2 to 6, as well as a composite number
, with its divisors being 1, 2, 3, 5, 6, 9, 15, 18, 30 and 45, and its factorization
In normal space, the interior angles of a square measure 90 degrees each. Also, in a right triangle, the angle opposing the hypotenuse measures 90 degrees, with the other two angles adding up to 90 for a total of 180 degrees.
See also: eighty, ninety, one hundred, integer, list of numbers.
Ninety is also: