15512
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 14
- Digital Root
- 5
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 16
- Divisor Sum
- 33360
- Proper Divisor Sum (Aliquot Sum)
- 17848
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 6624
- Möbius Function
- 0
- Radical
- 3878
- 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
- yes
- 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
- Expansion of tanh(log(1+x)*cosh(x)).at n=8A009784
- Number of binary [ n,3 ] codes.at n=22A034357
- Series expansion for mean-squared radius of gyration of staircase polygons on square lattice.at n=5A121779
- Lower triangular array called S2hat(-2) related to partition number array A144274.at n=49A144275
- Sum of divisors of Motzkin number A001006(n).at n=12A152981
- Numbers m such that A006218(m) is a perfect square.at n=37A175345
- a(n) = A014486(A179756(n)).at n=4A179757
- Number of (n+1) X 5 0..1 arrays with the number of rightwards and downwards edge increases in each 2 X 2 subblock equal to the number in all its horizontal and vertical neighbors.at n=13A206263
- Number of -3..3 arrays x(i) of n+1 elements i=1..n+1 with set{t,u,v in 0,1}((x[i+t]+x[j+u]+x[k+v])*(-1)^(t+u+v)) having two, three, four, five, six, seven or eight distinct values for every i,j,k<=n.at n=3A211766
- Number of rooted ordered trees with n non-root nodes such that the branch lengths are weakly decreasing.at n=12A246566
- Irreducible bridging trails on square lattice.at n=14A259856
- Irregular triangle read by rows: T(n,k) = number of size k subsets of S_n that remain unchanged by a rotation of 180 degrees.at n=44A277083
- Number T(n,k) of colored compositions of n using all colors of a k-set such that all parts have different color patterns and the patterns for parts i are sorted and have i colors in (weakly) increasing order; triangle T(n,k), n>=0, 0<=k<=n, read by rows.at n=32A327244
- Number of triangles in the graph formed by drawing the lines connecting any two of the 2*(n+2) perimeter points of a 3 X (n+1) rectangular grid of points (or equally, a 2 X n grid of squares).at n=17A332606
- Irregular triangle read by rows: consider the structure formed by drawing the lines connecting any two of the 2*(n+2) perimeter points of an (n+1) X 3 rectangular grid of points (or equally, an n X 2 grid of squares); row n gives number of cells with k sides, for k >= 3.at n=62A335701
- a(n) is the number of arches with a length of one and exactly one covering arch for semi-meanders with n top arches.at n=10A346757
- The smallest composite number k such that the digits of k and its prime factors, both written in base n, contain the same set of distinct digits.at n=53A372384
- E.g.f. satisfies A(x) = (1 + x * A(x)^2 * exp(x*A(x)^2))^2.at n=4A377633
- Number of integer partitions of n that cannot be partitioned into a set of sets.at n=40A382078
- G.f.: Sum_{k>=0} x^k * Product_{j=1..3*k} (1 + x^j).at n=51A385067