13040
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 8
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 20
- Divisor Sum
- 30504
- Proper Divisor Sum (Aliquot Sum)
- 17464
- 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
- 1630
- Omega Function (Ω)
- 6
- 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
- Boustrophedon transform of Catalan numbers 1, 1, 1, 2, 5, 14, ...at n=8A000736
- a(n) = 2*n*(4*n + 3).at n=40A033587
- Variant of Stanley's children's game. Class of n (named) children forms into rings of at least two with exactly one child inside each ring. a(n) gives number of possibilities, including clockwise order (or which hand is held), in each ring.at n=5A066165
- Lesser of two consecutive numbers each divisible by a fourth power.at n=25A068782
- Multiples of 8 with digit sum 8.at n=37A069543
- Starting positions of strings of three 2's in the decimal expansion of Pi.at n=18A083606
- Coefficients in a simultaneous approximation to Li(2,-1) and Li(3,-1).at n=3A098275
- a(n) = 16*(8*prime(n) + 7).at n=25A098823
- Consider the Levenshtein distance between k considered as a decimal string and k considered as a binary string. Then a(n) is the number of nonnegative integers having a Levenshtein distance of n.at n=13A115780
- Row sums of triangle A134464.at n=39A134465
- 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, 1, 1), (0, 1, -1), (0, 1, 1), (1, 0, -1)}.at n=9A148728
- Number of reduced words of length n in the Weyl group E_7 on 7 generators and order 2903040.at n=13A162493
- Number of 2:3:sqrt(13) proportioned triangles on a (n+1)X(n+1) grid.at n=16A190112
- Number of (n+1)X3 0..1 arrays with the sums of 2X2 subblocks nondecreasing rightwards and downwards.at n=5A204033
- Number of (n+1)X7 0..1 arrays with the sums of 2X2 subblocks nondecreasing rightwards and downwards.at n=1A204037
- T(n,k)=Number of (n+1)X(k+1) 0..1 arrays with the sums of 2X2 subblocks nondecreasing rightwards and downwards.at n=22A204039
- T(n,k)=Number of (n+1)X(k+1) 0..1 arrays with the sums of 2X2 subblocks nondecreasing rightwards and downwards.at n=26A204039
- Number of arrays of median of three adjacent elements of some length n+2 0..7 array, with no adjacent equal elements in the latter.at n=4A229011
- T(n,k) = number of arrays of median of three adjacent elements of some length n+2 0..k array, with no adjacent equal elements in the latter.at n=59A229012
- Number of arrays of median of three adjacent elements of some length 7 0..n array, with no adjacent equal elements in the latter.at n=6A229015