13086
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 18
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 12
- Divisor Sum
- 28392
- Proper Divisor Sum (Aliquot Sum)
- 15306
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 4356
- Möbius Function
- 0
- Radical
- 4362
- 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
- yes
- Narcissistic Number
- no
- Collatz Steps
- 138
- 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
- The array of A059578 read by antidiagonals in the 'up' direction.at n=33A059579
- Floor[ concatenation of n+4, n+3, n+2, n+1 and n divided by 5].at n=2A075006
- The (1,1)-entry in the 3 X 3 matrix M^n, where M = [1,2,1 / 2,2,0 / 1,0,0].at n=7A100191
- Number of columns ending at an even level in all deco polyominoes of height n. A deco polyomino is a directed column-convex polyomino in which the height, measured along the diagonal, is attained only in the last column.at n=6A121754
- Expansion of g.f.: x^2*(1-2*x) / (1-3*x-3*x^2+2*x^3).at n=9A123950
- a(0) = 1; a(n+1) = Sum_{k=0..n} a(n-k)*a(floor(k/2)).at n=14A127680
- Partial sums of A028388 good primes (version 2).at n=39A172166
- Smith numbers of order 3.at n=2A178213
- Triangular array read by rows: T(n,k) is the number of functions f:{1,2,...,n}->{1,2,...,n} with a height of k; n>=1, 0<=k<=n-1.at n=16A216242
- Expansion of (phi(x) / phi(x^2)) * (f(-x^3, -x^5) / f(-x^1, -x^7)) in powers of x where phi(), f() are Ramanujan theta functions.at n=37A245434
- a(0)=0, a(1)=1, a(n) = min{5 a(k) + (5^(n-k)-1)/4, k=0..(n-1)} for n>=2.at n=18A259669
- Array read by antidiagonals: T(n,m) is the number of acyclic edge covers of the complete bipartite graph K_{n,m}.at n=30A328888
- Array read by antidiagonals: T(n,m) is the number of acyclic edge covers of the complete bipartite graph K_{n,m}.at n=33A328888
- The number of lit cells in weakly decreasing partitions of n when light shines from the north west and only the first column is lit. Here partitions are represented from left to right by columns of cells.at n=25A366175
- Number of distinct partitions of length n binary strings into maximal constant substrings up to permutation.at n=22A380108