15568
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 25
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 20
- Divisor Sum
- 34720
- Proper Divisor Sum (Aliquot Sum)
- 19152
- 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
- 1946
- Omega Function (Ω)
- 6
- 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
- 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
- yes
- Odd
- no
Appears in sequences
- Expansion of tan(x)*cos(log(1+x)).at n=8A009726
- Number of sets S = {a_1, a_2, ..., a_k}, with 1 < a_i < a_j <= n such that no a_j divides the product of all the others.at n=22A023995
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 11 ones.at n=33A031779
- Gaps of 7 in sequence A038593 (upper terms).at n=36A038654
- (n+4)^3 - n^3.at n=33A038866
- Numbers n such that n*359# +-1 are twin primes, where 359# = 72nd primorial (A002110(72)).at n=17A087907
- Nonnegative values x of solutions (x, y) to the Diophantine equation x^2+(x+617)^2 = y^2.at n=7A115135
- Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 0), (-1, 0, 0), (1, -1, 0), (1, 1, 0), (1, 1, 1)}.at n=7A151021
- Second differences of A000219.at n=19A191660
- Number of (n+1) X 3 0..1 arrays with the number of clockwise edge increases in every 2 X 2 subblock the same.at n=4A205249
- Number of (n+1)X6 0..1 arrays with the number of clockwise edge increases in every 2X2 subblock the same.at n=1A205252
- T(n,k)=Number of (n+1)X(k+1) 0..1 arrays with the number of clockwise edge increases in every 2X2 subblock the same.at n=16A205255
- T(n,k)=Number of (n+1)X(k+1) 0..1 arrays with the number of clockwise edge increases in every 2X2 subblock the same.at n=19A205255
- Irregular triangle read by rows: T(n,k) (n>=2, 1<=k<=n) gives number of arrangements of the elements from the multiset M(n, 3) into exactly k disjoint cycles.at n=47A245183
- Expansion of phi(x) * chi(x^2)^4 in powers of x where phi(), chi() are Ramanujan theta functions.at n=46A260514
- Expansion of phi(x^2) * chi(x)^4 in powers of x where phi(), chi() are Ramanujan theta functions.at n=23A260515
- Number of nX5 0..1 arrays with every element unequal to 0, 1, 3 or 6 king-move adjacent elements, with upper left element zero.at n=11A304130
- Numbers k such that k and k+2 are both primitive practical numbers (A267124).at n=40A334882
- Square array read by antidiagonals: A(n,k) is the number of ordered solutions (x_1, x_2, ..., x_n) to equation phi(Product_{i=1..n} x_i) = k * Sum_{i=1..n} phi(x_i), or -1 if there are infinitely many solutions, n >= 1, k >= 1.at n=62A336710
- Expansion of e.g.f. cosh( (exp(2*x) - 1)/sqrt(2) ).at n=7A357661