720 (number)

Seven hundred twenty is the natural number following 719 and preceding 721.

720
Cardinal	Seven hundred and twenty
Ordinal	720th
Factorization	<math>2^4 \cdot 3^2 \cdot 5<math>
Roman numeral	DCCXX
Binary	1011010000
Hexadecimal	2D0

It is 6! (6 factorial), a composite number with lots of divisors, 1, 2, 3, 4, 5, 6, 8, 9, 10, 12, 15, 16, 18, 20, 24, 30, 36, 40, 45, 48, 60, 72, 80, 90, 120, 144, 180, 240, 360, 720, making it a highly composite number. It is a Harshad number in every base from binary to decimal.

There are 49 solutions to the equation φ(x) = 720, more than any integer below it, making 720 a highly totient number.

720 is a 241-gonal number.

See also: seven hundred

For the year AD, see 720.