15636
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 21
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 12
- Divisor Sum
- 36512
- Proper Divisor Sum (Aliquot Sum)
- 20876
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 5208
- Möbius Function
- 0
- Radical
- 7818
- Omega Function (Ω)
- 4
- Little Omega Function (ω)
- 3
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
- no
- Narcissistic Number
- no
- Collatz Steps
- 102
- 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
- Number of ways to cover (without overlapping) a ring lattice (necklace) of n sites with molecules that are 9 sites wide.at n=49A058364
- Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, -1), (-1, 0, 1), (0, 0, 1), (0, 1, 1), (1, 0, -1)}.at n=8A150079
- G.f. satisfies: A(x) = x + A(A(x))^2 + A(A(x))^4.at n=6A171991
- Number of partitions p of n such that (number of even numbers in p) <= (number of odd numbers in p).at n=37A241637
- G.f.: Sum_{n>=0} x^n * (1 + x^n)^n / (1 - x^(n+1))^(n+1).at n=51A325046
- a(n) is the number of edges formed by n-secting the angles of a square.at n=43A335527
- a(n) = n^2 + (1/n) * Sum_{k=1..n-1} binomial(n,k) * k * a(k) * (n-k)^2.at n=5A336183
- a(n) is the smallest positive integer which can be represented as the sum of distinct nonzero n-gonal pyramidal numbers in exactly n ways, or 0 if no such integer exists.at n=11A350210
- E.g.f. satisfies A(x) = exp(x * (1 + x)/A(x)^3).at n=5A365040