90 (number)

90 (number)

90 (ninety) is the natural number preceded by eighty-nine and followed by ninety-one.

90
Cardinal ninety
Ordinal ninetieth
Numeral system
Factorization
Roman numeral XC
Binary 1011010
Hexadecimal 5A

90
Cardinal	ninety
Ordinal	ninetieth
Numeral system
Factorization
Roman numeral	XC
Binary	1011010
Hexadecimal	5A

Mathematics

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.

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.

Other fields

Ninety is:

The atomic number of thorium, an actinide.
The designation of American Interstate 90, a freeway that runs from Washington to Massachusetts.
The code for international direct dial phone calls to Turkey.
The year AD 90.

89 and 91