15492
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
- 36176
- Proper Divisor Sum (Aliquot Sum)
- 20684
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 5160
- Möbius Function
- 0
- Radical
- 7746
- 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
- 53
- 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 key permutations of length n: permutations {a_i} with |a_i - a_{i-1}| = 1 or 2.at n=21A003274
- Conjectured number of irreducible multiple zeta values of depth 10 and weight 2n+28.at n=11A022498
- a(n) = self-convolution of row n of array T given by A027170.at n=4A027182
- Numbers whose set of base-9 digits is {2,3}.at n=39A032809
- Ratio of each term of the primorial function to the corresponding term of the factorial function (rounded to nearest integer).at n=11A123389
- G.f. 1/(1-6*x*c(x)) where c(x) is the g.f. of A000108.at n=5A127628
- a(n) = floor( Product_{i=1..n} prime(i)/i ).at n=12A135568
- First differences of A145646.at n=7A145647
- a(n) = n*(2*n^2 + 5*n + 19)/2.at n=24A163675
- Number of binary strings of length n with equal numbers of 0010 and 1001 substrings.at n=15A164169
- Number of ordered triples (w,x,y) with all terms in {1,...,n} and w^2+x^2+y^2>2n.at n=25A211644
- a(1) = 16. For n > 1, a(n) is the position of the first occurrence of a(n-1) after the decimal point in the decimal expansion of Pi.at n=7A247345
- a(1) = 16. For n > 1, a(n) is the position of the first occurrence of a(n-1) after the decimal point in the decimal expansion of Pi.at n=27A247345
- Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 573", based on the 5-celled von Neumann neighborhood.at n=23A272997
- p-INVERT of (0,1,0,1,0,1,...), where p(S) = (1 - 2 S)^2.at n=8A291264
- Numbers that are the sum of eight fourth powers in exactly seven ways.at n=37A345839
- a(n) is the sum of the squares of the areas under Motzkin paths of length n.at n=7A367778