15948
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 27
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 18
- Divisor Sum
- 40404
- Proper Divisor Sum (Aliquot Sum)
- 24456
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 5304
- Möbius Function
- 0
- Radical
- 2658
- Omega Function (Ω)
- 5
- 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 partitions into non-integral powers.at n=18A000263
- Numbers k such that k!!! + 1 is prime (0 is included by convention).at n=35A037083
- a(n) = a(1) + a(2) + ... + a(n-1) + a(m) for n >= 4, where m = n - 1 - 2^p and p is the unique integer such that 2^p < n - 1 <= 2^(p+1), starting with a(1) = 1, a(2) = 3, and a(3) = 2.at n=14A049970
- Number of ways of numbering the faces of a cube with nonnegative integers so that the sum of the 6 numbers is n.at n=31A054473
- Number of permutations of length n which avoid the patterns 2134, 3241, 4132.at n=9A116810
- Number of columns with an even sum in all 2-compositions of n. A 2-composition of n is a nonnegative matrix with two rows, such that each column has at least one nonzero entry and whose entries sum up to n.at n=8A181328
- Number of (n+1)X(1+1) 0..2 arrays colored with the upper median plus the lower median minus the minimum of every 2X2 subblock.at n=3A237678
- Number of (n+1)X(4+1) 0..2 arrays colored with the upper median plus the lower median minus the minimum of every 2X2 subblock.at n=0A237681
- T(n,k)=Number of (n+1)X(k+1) 0..2 arrays colored with the upper median plus the lower median minus the minimum of every 2X2 subblock.at n=6A237683
- T(n,k)=Number of (n+1)X(k+1) 0..2 arrays colored with the upper median plus the lower median minus the minimum of every 2X2 subblock.at n=9A237683
- Sums of Pythagorean sextuples in increasing order: The sums of sets of six natural numbers which correspond to the lengths of the edges of a tetrahedron whose four faces are all different Pythagorean triangles.at n=26A248548
- Number of ways to tile an n X n X n triangular area with two 2 X 2 X 2 triangular tiles and an appropriate number (= n^2-8) of 1 X 1 X 1 tiles.at n=12A286437
- Numbers k such that there is no prime p and index j > k such that A002182(j) = p * A002182(k).at n=5A309042
- Numbers k such that k and 4k, taken together, contain all digits 1 though 9 at least once.at n=20A346135
- a(n) = Sum_{k=0..n} binomial(n+2*k-1,n-k) * Catalan(k).at n=7A360100
- G.f.: Sum_{k>=0} x^(k*(k+1)/2) / Product_{j=1..k} (1 - x^(2*j-1))^2.at n=39A376624