720
domain: N
Properties
Digital Properties
- Digit Count
- 3
- Digit Sum
- 9
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 30
- Divisor Sum
- 2418
- Proper Divisor Sum (Aliquot Sum)
- 1698
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Highly Composite
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 192
- Möbius Function
- 0
- Radical
- 30
- Omega Function (Ω)
- 7
- Little Omega Function (ω)
- 3
Special
- Factorial
- yes
- Catalan Number
- no
- Bell Number
- no
- Motzkin Number
- no
- Primorial
- no
Figurate Numbers
- Fibonacci Number
- no
- Triangular Number
- no
- Perfect Square
- no
- Perfect Cube
- no
- Pentagonal Number
- no
- Hexagonal Number
- no
- Lucas Number
- no
- Tetrahedral Number
- no
- Pell Number
- no
- Tribonacci Number
- no
- Pronic Number
- no
Recreational
- Happy Number
- no
- Harshad Number
- yes
- Narcissistic Number
- no
- Collatz Steps
- 20
- Smith Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- Squarefree Number
- no
- Prime Power
- no
- Prime Factorization
- no
- Twin Prime
- no
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Perfect Power
- no
- Smooth Number
- yes
- Carmichael Number
- no
Classification
- Even
- yes
- Odd
- no
Names
- German
- siebenhundertzwanzig· ordinal: siebenhundertzwanzigste
- English
- seven hundred twenty· ordinal: seven hundred twentieth
- Spanish
- setecientos veinte· ordinal: 720º
- French
- sept cent vingt· ordinal: sept cent vingtième
- Italian
- settecentoventi· ordinal: 720º
- Latin
- septingenti viginti· ordinal: 720.
- Portuguese
- setecentos e vinte· ordinal: 720º
Appears in sequences
- Order of the group SL(2,Z_n).at n=9A000056
- a(n) = n^2*Product_{p|n} (1 + 1/p).at n=19A000082
- Number of cusps of principal congruence subgroup Gamma^{hat}(n).at n=42A000114
- Number of self-complementary graphs with n nodes.at n=11A000171
- a(n) = (n!)!.at n=3A000197
- a(n) = Sum_{k=1..n-1} k^2*sigma(k)*sigma(n-k).at n=5A000477
- Number of labeled trees of diameter 4 with n nodes.at n=1A000555
- Permanent of a certain cyclic n X n (0,1) matrix.at n=6A000805
- a(n) = (2*n)!*(2*n+1)! / n!^2.at n=2A000909
- Differences of 0: 6!*Stirling2(n,6).at n=5A000920
- Jordan-Polya numbers: products of factorial numbers A000142.at n=27A001013
- Sorted list of orders of Weyl groups of types A_n, B_n, D_n, E_n, F_4, G_2.at n=11A001217
- Numbers k such that phi(sigma(k)) = k.at n=6A001229
- Number of partitions of n into at most 4 parts.at n=42A001400
- n-phi-torial, or phi-torial of n: Product k, 1 <= k <= n, k relatively prime to n.at n=6A001783
- Coefficients of x^n in Hermite polynomial H_{n+4}.at n=2A001816
- Highly abundant numbers: numbers k such that sigma(k) > sigma(m) for all m < k.at n=40A002093
- Generalized sum of divisors function.at n=23A002132
- Highly composite numbers: numbers n where d(n), the number of divisors of n (A000005), increases to a record.at n=13A002182
- Number of divisors of n-th highly composite number.at n=54A002183