Eighty-five

The eighty-five (85) is the natural number that follows eighty-four and precedes eighty-six.

Mathematical properties

• It is a composite number, which has the following factors: 1, 5 and 17. Since the sum of its factors is 23 ≤ 85, it is a poor number.

• It is the smallest number that can be expressed as a sum of two squares in two different ways: 85 = 22 + 92 = 62 + 72.

Features

• 85 is the atomic number of the astatus.