15765
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
- 8
- Divisor Sum
- 25248
- Proper Divisor Sum (Aliquot Sum)
- 9483
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 8400
- Möbius Function
- -1
- Radical
- 15765
- Omega Function (Ω)
- 3
- 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
- 27
- 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
- no
- Odd
- yes
Appears in sequences
- Number of partitions of n into at most 8 parts.at n=44A008637
- Number of partitions of n in which the greatest part is 8.at n=52A026814
- Number of n-node rooted identity trees of height 8.at n=9A038092
- Triangle read by rows: T(n,k) is the number of compositions of n into k parts when parts equal to q are of q^2 kinds.at n=50A105495
- Number of compositions of n with parts in N which avoid the adjacent pattern 111.at n=16A128695
- This is to A139025 as A139025 to A014688, see A139025 for details.at n=25A139026
- a(n) = [x^n] Product_{k=1..n} 1/(x^k*(1-x^k)).at n=8A258788
- Coefficient of y^0 in G(x,y)^3 where G(x,y) = Sum_{n=-oo..+oo} (1-x^n)^n * x^n * y^n.at n=60A263188
- Number of partitions of n such that least and largest parts are distinct and occur the same number of times.at n=45A265259
- Sum of the sixth largest parts in the partitions of n into 7 parts.at n=47A308928
- G.f. A(x) = Sum_{n>=0} a(n)*x^n satisfies: [Sum_{n>=0} x^n/(1 - x^(n+1))]^3 = Sum_{n>=0} a(n)*x^n/(1 - x^(n+1))^3.at n=37A341374
- a(n) = Product_{i=n..n+4} A000045(i) mod Sum_{i=n..n+4} A000045(i).at n=17A348914
- Square array T(n,k), n >= 1, k >= 1, read by antidiagonals downwards, where T(n,k) = Sum_{j=1..n} j * floor(n/j)^k.at n=49A350106
- Number of fixed site animals with n nodes on the nodes of the floret pentagonal tiling.at n=7A379052