2640
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 12
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 40
- Divisor Sum
- 8928
- Proper Divisor Sum (Aliquot Sum)
- 6288
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 640
- Möbius Function
- 0
- Radical
- 330
- Omega Function (Ω)
- 7
- Little Omega Function (ω)
- 4
Special
- Factorial
- no
- 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
- 115
- Smith Number
- no
- Vampire 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
- no
- Carmichael Number
- no
Classification
- Even
- yes
- Odd
- no
Appears in sequences
- Partial sums of (unordered) ways of making change for n cents using coins of 1, 2, 5, 10 cents.at n=41A000064
- Octagonal numbers: n*(3*n-2). Also called star numbers.at n=30A000567
- Number of partitions of n into parts of 3 kinds.at n=10A000716
- Generalized Stirling numbers, [n+2,n]_2.at n=10A001701
- Expansion of (1-x)^(-3) * (1-x^2)^(-2).at n=19A002624
- Degrees of irreducible representations of symmetric group S_12.at n=55A003876
- a(n) = ceiling(1000*log(n)).at n=13A004242
- a(n) = 5*a(n-1) - a(n-2) for n > 1, a(0) = 0, a(1) = 1.at n=6A004254
- a(n) = n*(n+1)*(n+2)^2/6.at n=10A004320
- Number of permutations of (1,...,n) having n-7 inversions (n>=7).at n=5A005285
- a(n) = C(n,5) + C(n,4) - C(n,3) + 1, n >= 7.at n=8A005288
- Number of labeled regular tournaments with 2n+1 nodes.at n=3A007079
- Number of spanning trees of quarter Aztec diamonds of order n.at n=4A007726
- Coordination sequence T2 for Zeolite Code BIK.at n=31A008048
- Coordination sequence T1 for Zeolite Code MOR.at n=33A008182
- Coordination sequence T2 for Zeolite Code -PAR.at n=36A009856
- a(n) = (n+1)*(2*n+1)*(3*n+1).at n=7A011199
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly three 1's.at n=36A013650
- a(n) is nonsquarefree and is sum of first k nonsquarefrees for some k.at n=20A013935
- Even octagonal numbers: a(n) = 4*n*(3*n-1).at n=15A014642