15108
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 15
- Digital Root
- 6
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 12
- Divisor Sum
- 35280
- Proper Divisor Sum (Aliquot Sum)
- 20172
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 5032
- Möbius Function
- 0
- Radical
- 7554
- 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
- yes
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 133
- 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
- E.g.f.: A(x) = Product_{n>=0} [1 + Sum_{k>=n+1} C(k-1,n)*x^k/k! ].at n=8A129482
- a(n) = (2*n^3 + 5*n^2 - 13*n)/2.at n=23A162262
- Let S(1)={1} and, for n>1 let S(n) be the smallest set containing x+1, x+2, and 2*x for each element x in S(n-1). a(n) is the number of elements in S(n).at n=18A168043
- Coefficient expansion of: f(t,y)=((1 + y)/y - Exp[t/2])/(-1 + y*Exp[t]).at n=23A171721
- Diagonal sums of triangle A182013.at n=11A182015
- 1-sequence of reduction of (2n) by x^2 -> x+1.at n=13A192306
- Number of binary arrays indicating the locations of trailing edge maxima of a random length-n 0..7 array extended with zeros and convolved with 1,1.at n=19A222333
- Numbers n such that sigma(n+sigma(n)) = 4*sigma(n).at n=35A246911
- Triangle read by rows: T(n, k) is the number of ways to select k disjoint point triples from an n X n X n triangular point grid, each point triple forming a 2 X 2 X 2 triangle.at n=29A289222
- Number of ways to select 5 disjoint point triples from an n X n X n triangular point grid, each point triple forming a 2 X 2 X 2 triangle.at n=2A289226
- The first Zagreb index of the Aztec diamond AZ(n) (see the Ramanes et al. reference, Theorem 2.1).at n=20A292344
- Number of nX3 0..1 arrays with every element equal to 2, 3, 4 or 6 king-move adjacent elements, with upper left element zero.at n=8A298065
- T(n,k)=Number of nXk 0..1 arrays with every element equal to 2, 3, 4 or 6 king-move adjacent elements, with upper left element zero.at n=57A298070
- Number T(n,k) of proper k-times partitions of n; triangle T(n,k), n >= 0, 0 <= k <= max(0,n-1), read by rows.at n=55A327639
- Number of refinement sequences n -> ... -> {1}^n, where in each step one part is replaced by a partition of itself into two smaller parts (in weakly decreasing order).at n=9A327643
- The number of regions inside a vesica piscis formed by the straight line segments mutually connecting all vertices and all points that divide the sides into n equal parts.at n=12A341877
- Number of ways to write n as an ordered sum of nine powers of 2.at n=21A342252