← 719 720 721 →
Cardinalseven hundred twenty
Ordinal720th
(seven hundred twentieth)
Factorization24 × 32 × 5
Divisors1, 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
Greek numeralΨΚ´
Roman numeralDCCXX
Binary10110100002
Ternary2222003
Octal13208
Duodecimal50012

720 (seven hundred [and] twenty) is the natural number following 719 and preceding 721.

It is 6! (6 factorial), a composite number with thirty divisors, more than any number below, making it a highly composite number. It is a Harshad number in every base from binary to decimal.

720 is expressible as the product of consecutive integers in two different ways: 720 = 1 × 2 × 3 × 4 × 5 × 6 , and 720 = 8 × 9 × 10 . [1]

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.

## In other fields

720 is:

For the year AD, see 720.

## References

1. ^ Wells, David (1987). The Penguin Dictionary of Curious and Interesting Numbers. London: Penguin Books. p. 719.