15385
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 22
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 19656
- Proper Divisor Sum (Aliquot Sum)
- 4271
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 11520
- Möbius Function
- -1
- Radical
- 15385
- 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
- 177
- 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
- Numbers n such that phi(n + 1) | sigma(n) for n congruent to 1 (mod 3).at n=35A015817
- Product of prime p with sum of next p consecutive primes.at n=6A036660
- Shadow of Euler's constant exp(1).at n=40A108912
- Number of ways to place zero or more nonadjacent 1,1 2,0 2,1 3,2 4,1 4,2 5,3 polyhexes in any orientation on a planar nXnXn triangular grid.at n=7A155342
- Number of (w,x,y) with all terms in {0,...,n} and w<=x+y and x<=y.at n=32A212983
- Principal diagonal of the convolution array A213579.at n=13A213580
- a(n) = (n + 1)*(20*n^2 + 19*n + 6)/6.at n=16A220084
- Heinz numbers of integer partitions into relatively prime parts whose reciprocal sum is the reciprocal of an integer.at n=8A316901
- a(n) = Sum_{k=1..n} floor(n/k)^4.at n=10A318743
- a(n) = A379597(n) - A381710(n).at n=43A381711