15564
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
- 36344
- Proper Divisor Sum (Aliquot Sum)
- 20780
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 5184
- Möbius Function
- 0
- Radical
- 7782
- 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
- yes
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 40
- 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 n-node trees of height at most 4.at n=15A001384
- Numbers whose base-4 representation contains exactly three 0's and four 3's.at n=14A045080
- Open 3-dimensional ball numbers (version 3): a(n) is the number of integer points (i,j,k) contained in an open ball of diameter n, centered at (1/2,1/2,0).at n=31A053595
- Numbers k such that phi(k) divides (sigma(k+1) + sigma(k-1)).at n=42A067244
- Interprimes which are of the form s*prime, s=12.at n=38A075287
- Row sums of A094307.at n=8A094308
- Binomial transform of A079619, assuming offset zero there.at n=13A105143
- Number of self-avoiding walks of n steps on a Manhattan square lattice.at n=16A117633
- Number of graphs on n labeled nodes with maximal degree exactly 2.at n=6A136284
- Row sums of Riordan array ((1-3x)/(1-4x+x^2), x(1-x)/(1-4x+x^2)).at n=7A147722
- Partial sums of A024012.at n=13A174120
- Triangle read by rows: T(n,k) = Sum_{c in C(n,k)} lcm(c) where C(n,k) is the set of all k-subsets of {1,2,...,n}.at n=53A181853
- Number of n X 3 0..4 arrays with each element equal to the number its horizontal and vertical neighbors within one of itself.at n=16A196012
- Number of -n..n arrays x(0..3) of 4 elements with zero sum and nonzero second and third differences.at n=13A200205
- Number of (n+1)X6 0..1 arrays with every 2X2 subblock having equal diagonal elements or equal antidiagonal elements.at n=1A203375
- T(n,k)=Number of (n+1)X(k+1) 0..1 arrays with every 2X2 subblock having equal diagonal elements or equal antidiagonal elements.at n=16A203378
- T(n,k)=Number of (n+1)X(k+1) 0..1 arrays with every 2X2 subblock having equal diagonal elements or equal antidiagonal elements.at n=19A203378
- Number of (n+1) X 2 0..3 arrays with the number of clockwise edge increases in 2 X 2 subblocks nondecreasing, and counterclockwise edge increases nonincreasing, rightwards and downwards.at n=2A206102
- Number of (n+1) X 4 0..3 arrays with the number of clockwise edge increases in 2 X 2 subblocks nondecreasing, and counterclockwise edge increases nonincreasing, rightwards and downwards.at n=0A206104
- T(n,k) = number of (n+1) X (k+1) 0..3 arrays with the number of clockwise edge increases in 2 X 2 subblocks nondecreasing, and counterclockwise edge increases nonincreasing, rightwards and downwards.at n=3A206109