720 (number)

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719 720 721
Cardinal seven hundred twenty
Ordinal 720th
(seven hundred and twentieth)
Factorization 24× 32× 5
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
Roman numeral DCCXX
Binary 10110100002
Ternary 2222003
Quaternary 231004
Quinary 103405
Senary 32006
Octal 13208
Duodecimal 50012
Hexadecimal 2D016
Vigesimal 1G020
Base 36 K036

Seven hundred 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[edit]

720 is

For the year AD, see 720.

References[edit]

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