15918
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
- 16
- Divisor Sum
- 36480
- Proper Divisor Sum (Aliquot Sum)
- 20562
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 4536
- Möbius Function
- 1
- Radical
- 15918
- Omega Function (Ω)
- 4
- 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
- 97
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- Squarefree Number
- yes
- 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
- Number of site swap patterns with 2 balls and exact period n.at n=10A065178
- McKay-Thompson series of class 16a for the Monster group.at n=17A112150
- Number of permutations of length n which avoid the patterns 2134, 2143, 4312.at n=9A116754
- Numbers k such that 5^k mod k = 5^k mod k^2.at n=31A125775
- Quotients (3^p - 2^p - 1)/p, where p = prime(n).at n=4A127071
- Numbers k such that k^2 divides 5^k-1.at n=25A127105
- Triangular sequence of coefficients from a polynomial recursion: p(x,n)=-2 (-(n - 1) + x)*p(x, n - 1) + (-(n + 1) + (n + 2)* x - x^2)p(x, n - 2).at n=40A137663
- a(n) = 36*n^2 + 2*n.at n=20A158064
- a(n) = floor((3^n - 2^n)/n).at n=10A191694
- Expansion of chi(x^5)^6 + x * chi(x)^6 in powers of x where chi() is a Ramanujan theta function.at n=18A240948
- Number of length n+5 0..2 arrays with no six consecutive terms having the maximum of any two terms equal to the minimum of the remaining four terms.at n=7A249954
- Number of length 4 1..(n+1) arrays with every leading partial sum divisible by 2, 3, 5 or 7.at n=13A258635
- Triangle read by rows: T(n,k) number of ways of partitioning the (n+5)-element multiset {1,1,1,1,1,1,2,3,...,n} into exactly k nonempty parts, n >= 0 and 1 <= k <= n + 5.at n=60A291120
- Antidiagonal sums of the first quadrant of array A(k,m) = F_k(m), F_k(m) being the k-th Fibonacci polynomial evaluated at m.at n=11A304357
- Number of equivalence classes of convex lattice polygons of genus n, restricting the count to those polygons that are interior to another polygon.at n=27A322344
- Inverse Weigh transform of 3^(n-1).at n=10A383035