15558
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
- 31128
- Proper Divisor Sum (Aliquot Sum)
- 15570
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- yes
Derived Values
- Euler's Totient
- 5184
- Möbius Function
- -1
- Radical
- 15558
- 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
- 40
- Smith Number
- yes
- 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
- a(n) = s(1)*s(n) + s(2)*s(n-1) + ... + s(k)*s(n+1-k), where k = floor((n+1)/2), s = (odd natural numbers).at n=35A024598
- a(n) = s(1)s(n) + s(2)s(n-1) + ... + s(k)s(n-k+1), where k = floor(n/2), s = (odd natural numbers).at n=34A025112
- Open 3-dimensional ball numbers (version 2): a(n) is the number of integer points (i,j,k) contained in an open ball of diameter n, centered at (1/2,0,0).at n=31A053594
- a(n) = n*(8*n^2 + 1)/3.at n=18A143166
- Number of 1-sided strip polypons with n cells.at n=29A151532
- a(n) = n*(n+1)*(2*n+1)/6 - n*floor(n/2).at n=35A178946
- Numbers k such that phi(k-6) = phi(k) = phi(k+6).at n=21A217006
- Expansion of (1/(1 - x))*Product_{k>=1} (1 - x^prime(k))/(1 - x^k).at n=45A303663
- Number of edges in a hexagon when n internal hexagons are drawn between the 6n points that divide each side into n+1 equal parts.at n=36A357198