15988
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 31
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 12
- Divisor Sum
- 32032
- Proper Divisor Sum (Aliquot Sum)
- 16044
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- yes
Derived Values
- Euler's Totient
- 6840
- Möbius Function
- 0
- Radical
- 7994
- Omega Function (Ω)
- 4
- 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
- 53
- 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
- a(n) = (d(n)-r(n))/2, where d = A026049 and r is the periodic sequence with fundamental period (1,0,0,1).at n=41A026050
- "BFK" (reversible, size, unlabeled) transform of 1,2,3,4...at n=15A032045
- Number of distinct products i*j*k*l for 1 <= i < j < k < l <= n.at n=39A100438
- Number of ways to place 3n nonattacking kings on a 6 X 2n cylindrical chessboard.at n=5A194645
- Number of ways to place 6n nonattacking kings on a vertical cylinder 12 X 2n.at n=2A195594
- Number of partitions p of n such that if h = min(p), then h is an (h,0)-separator of p; see Comments.at n=51A239510
- Index where n first appears in A381658.at n=52A381659