720 (number)

Summary

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

← 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
Senary32006
Octal13208
Duodecimal50012
Hexadecimal2D016

In mathematics

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720 is:

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.[4]

There are 49 solutions to the equation φ(x) = 720, more than any integer below it, making 720 a highly totient number.[5]


In other fields

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720 is:

For the year AD, see 720.

References

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  1. ^ Sloane, N. J. A. (ed.). "Sequence A002182 (Highly composite numbers)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
  2. ^ Sloane, N. J. A. (ed.). "Sequence A002093 (Highly abundant numbers: numbers k such that sigma(k) > sigma(m) for all m < k)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
  3. ^ Sloane, N. J. A. (ed.). "Sequence A037183 (Smallest number that is palindromic (with at least 2 digits) in n bases)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
  4. ^ Wells, David (1987). The Penguin Dictionary of Curious and Interesting Numbers. London: Penguin Books. p. 719.
  5. ^ Sloane, N. J. A. (ed.). "Sequence A097942 (Highly totient numbers: each number k on this list has more solutions to the equation phi(x) = k than any preceding k)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.