15556
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 22
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 6
- Divisor Sum
- 27230
- Proper Divisor Sum (Aliquot Sum)
- 11674
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 7776
- Möbius Function
- 0
- Radical
- 7778
- Omega Function (Ω)
- 3
- Little Omega Function (ω)
- 2
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
- 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
- Numbers having four 0's in base 6.at n=33A043372
- Number of basis partitions of n+25 with Durfee square size 5.at n=34A053800
- a(n) = A014486(A122238(n)).at n=4A122239
- Total number of line segments between points visible to each other in a square n X n lattice.at n=14A141255
- Numbers n such that phi(n)=phi(n+5), with Euler's totient function phi=A000010.at n=4A179187
- 1/3 the number of n X n 0..2 symmetric matrices with every element equal to zero, one, two or four horizontal and vertical neighbors.at n=3A211048
- a(n) is the smallest positive integer such that 10^(2 + floor(k/a(1)) + floor(k/a(2)) + ... + floor(k/a(n))) divides (k+9)! for all k > 0.at n=10A218976
- Integers n where n^3 + (n+1)^3 is a Taxicab number A001235.at n=9A259836
- Number of (n+2)X(6+2) 0..1 arrays with each row divisible by 5 and column not divisible by 5, read as a binary number with top and left being the most significant bits.at n=0A262793
- T(n,k)=Number of (n+2)X(k+2) 0..1 arrays with each row divisible by 5 and column not divisible by 5, read as a binary number with top and left being the most significant bits.at n=15A262795
- Number of (1+2)X(n+2) 0..1 arrays with each row divisible by 5 and column not divisible by 5, read as a binary number with top and left being the most significant bits.at n=5A262796
- Number of active (ON, black) cells at stage 2^n-1 of the two-dimensional cellular automaton defined by "Rule 398", based on the 5-celled von Neumann neighborhood.at n=7A271694
- a(n) is the number of partitions of 72*n + 42 into 10 odd squares.at n=37A323891
- Expansion of e.g.f. exp(cosh(exp(x) - 1) - 1).at n=8A330041
- a(n) = Sum_{-n<i<n, -n<j<n, gcd{i,j}=2} (n-|i|)*(n-|j|)/8.at n=29A331773
- a(n) = Sum_{1 <= i, j, k, l <= n} gcd(i,j,k,l).at n=10A344523
- Number of integer partitions of n such that it is possible to choose a different constant integer partition of each part.at n=48A387330