15675
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 24
- Digital Root
- 6
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 24
- Divisor Sum
- 29760
- Proper Divisor Sum (Aliquot Sum)
- 14085
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 7200
- Möbius Function
- 0
- Radical
- 3135
- 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
- 102
- 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
- 4-dimensional pyramidal numbers: a(n) = (3*n+1)*binomial(n+2, 3)/4. Also Stirling2(n+2, n).at n=18A001296
- a(n) = n*(n + 1)*(n^2 - 3*n + 5)/6.at n=18A006484
- Number of partially ordered sets with no isolated points and with n "lines": pairs (a,b) where a < b and there is no c with a < c < b. The lines form the minimal basis for the partial ordering.at n=8A022016
- Denominators of continued fraction convergents to sqrt(629).at n=5A042207
- a(n) = Sum_{d|3} phi(d)*n^(3/d).at n=25A054602
- Sequence resulting from a sum of three repeated binomial(n+3,4) sequences.at n=34A093039
- G.f. A(x) satisfies: 2^n - 1 = Sum_{k=0..n} [x^k]A(x)^n and also satisfies: (2+z)^n - (1+z)^n + z^n = Sum_{k=0..n} [x^k](A(x)+z*x)^n for all z, where [x^k]A(x)^n denotes the coefficient of x^k in A(x)^n.at n=19A100223
- a(n) = (n-1)*(n+2)*(2*n+11)/2.at n=22A130862
- Triangle T(n,k) read by rows = number of partitions of n-set into k blocks with distinct sizes, k = 1..A003056(n).at n=26A131632
- Column 3 of triangle in A133721.at n=54A133722
- A122890 + A000012 - I, I = Identity matrix.at n=50A135723
- The PolyLog functional part of A008292 (the Eulerian numbers) is treated as a curvature to give a set of polynomial triangle sequence coefficients: p(x,n)=Sum[A008292(n,m)*x^(m-1),{m,0,n}]; q(x,n)=k from Solve[FullSimplify[ExpandAll[p[x, n]/(x - 1)^n]] - (1 + k/x^2) == 0, k].at n=38A146540
- a(n) = 25*n^2 + 2*n.at n=24A154377
- Euler transform of Fibonacci numbers.at n=16A166861
- a(n) = n*(16*n^2 + 3*n - 13)/6.at n=18A172078
- Coefficient of x in the reduction by x^2->x+2 of the polynomial p(n,x) defined below in Comments.at n=5A192459
- a(n) = n*(14*n + 13).at n=33A195028
- a(-1) = 1 and g.f. A(x) satisfies A(x) - 1/A(x) = 1/x - 1.at n=19A214649
- The Wiener index of the nanostar dendrimer NS[n], defined pictorially in the Wang-Hua reference.at n=2A221004
- Irregular triangle read by rows: the W-transformation of the Catalan triangle A033184.at n=32A228337