15020
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
- 12
- Divisor Sum
- 31584
- Proper Divisor Sum (Aliquot Sum)
- 16564
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 6000
- Möbius Function
- 0
- Radical
- 7510
- 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
- 63
- 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
- S(n,n) + S(n-1,n-2) + S(n-2,n-4) + ... + S(n-k+1,n-2k+2), where k = [ (n+1)/2 ] and S(i,j) are Stirling numbers of second kind.at n=12A024428
- a(n) = Sum_{k=1..n+1} A027960(n+1, n+1+k).at n=11A027974
- Duplicate of A027974.at n=11A027983
- Numbers whose base-5 representation contains exactly three 0's and three 4's.at n=7A045217
- a(0)=a(1)=1. For n >= 2, if a(n-1) is coprime to n, then a(n) = a(n-1) + a(n-2). Otherwise, a(n)=1.at n=47A139047
- Inverse binomial transform of A014217.at n=15A142585
- a(n) = 1000*n + 20.at n=14A157510
- G.f.: Sum_{n>=0} x^n / Product_{k=1..2*n-1} (1 - k*x).at n=7A229285
- Number of overcompositions of n minus the number of compositions of n.at n=12A236633
- Numbers n such that Bernoulli number B_{n} has denominator 330.at n=39A272183
- Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 825", based on the 5-celled von Neumann neighborhood.at n=23A273581
- a(n) = 12*n^2 + 10*n - 30.at n=35A277982
- Expansion of Product_{k>=1} 1/(1 - x^(k*(k+1)/2))^2.at n=38A298435
- Number of non-isomorphic multiset partitions of weight n where each part has a different length.at n=11A326026