15939
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
- 3
Divisibility
- Divisor Count
- 24
- Divisor Sum
- 29952
- Proper Divisor Sum (Aliquot Sum)
- 14013
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 7920
- Möbius Function
- 0
- Radical
- 5313
- Omega Function (Ω)
- 5
- Little Omega Function (ω)
- 4
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
- no
- Odd
- yes
Appears in sequences
- Number of rotationally symmetric polyominoes with n cells (that is, polyominoes with exactly the symmetry group C_2 generated by a 180-degree rotation).at n=17A006747
- a(n) = floor(n*(n-1)*(n-2)*(n-3)/16).at n=24A011926
- Powers of cube root of 14 rounded down.at n=11A018015
- Powers of cube root of 14 rounded to nearest integer.at n=11A018016
- Number of independent components for a Weyl tensor in n dimensions.at n=18A052472
- Number of partitions of n in SPM(n): these are the partitions obtained from (n) by iteration of the following transformation: p -> p' if p' is a partition (i.e., decreasing) and p' is obtained from p by removing a unit from the i-th component of p and adding one to the (i+1)-th component, for any i.at n=48A056219
- Consider recurrence b(0) = (2n+1)/2, b(n) = b(n-1)*floor(b(n-1)); sequence gives first integer reached.at n=9A057016
- Triangle read by rows: T(n,k) = binomial(3n+3, k)*(n-k+1)/(n+1).at n=33A064282
- Pair the odd numbers such that the k-th pair is (r, r+2k) where r is the smallest odd number not included earlier: (1, 3), (5, 9), (7, 13), (11, 19), (15, 25), (17, 29), (21, 35), (23, 39), (27, 45), ... This is the sequence of the product of the members of pairs.at n=30A075320
- Fifth column of the (1,4)-Pascal triangle A095666.at n=20A095667
- Denominators of e.g.f. sec(arccosh(x)) = cosec(arcsinh(x)).at n=43A102074
- A002415 and A052472 interlaced.at n=40A117651
- a(n) = floor(n*(n+2)*(n+4)*(n-6)/192).at n=42A117652
- Inverse of Riordan array (1/(1+x)^3, x/(1+x)^3).at n=30A127898
- Triangle, read by rows, such that the g.f. of column k = G(x)^(2k+1) where G(x) = 1 + x*G(x)^3 is the g.f. of A001764 (ternary trees).at n=49A143603
- Numerators of triangle T(n,k), n>=0, 0<=k<=n, read by rows: T(n,k) is the coefficient of x^(2k+1) in polynomial u_n(x), used to approximate x->sin(Pi*x)/Pi.at n=17A144846
- 3 times 12-gonal (or dodecagonal) numbers: a(n) = 3*n*(5*n-4).at n=33A153448
- Array A(n, k) = (1/2)*(2*n+1)!!*(2*k+1)!!*Integral_{x=-1..1} (1-x^(n+1))*(1-x^(k+1))/(1-x)^2 dx, read by antidiagonals.at n=15A157050
- Array A(n, k) = (1/2)*(2*n+1)!!*(2*k+1)!!*Integral_{x=-1..1} (1-x^(n+1))*(1-x^(k+1))/(1-x)^2 dx, read by antidiagonals.at n=20A157050
- Numbers k for which 5*k-4, 5*k-2, 5*k+2, and 5*k+4 are primes.at n=31A178082