15598
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 28
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 25560
- Proper Divisor Sum (Aliquot Sum)
- 9962
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 7080
- Möbius Function
- -1
- Radical
- 15598
- 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
- 146
- 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
- Gaps of 10 in sequence A038593 (lower terms).at n=11A038659
- Number of nondecreasing integer sequences of length 9 with sum zero and sum of absolute values 2n.at n=16A158143
- Antidiagonal sums of A147995 and A163545.at n=26A163484
- Number of different hook length multisets of partitions of n.at n=39A180652
- Monotonic ordering of nonnegative differences 5^i-3^j, for 40>=i>=0, j>=0.at n=30A192150
- Volume of sphere (rounded down) with the diameter equal to n.at n=30A228272
- Number of Mersenne number parts in all partitions of n.at n=27A264395
- Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 173", based on the 5-celled von Neumann neighborhood.at n=28A270467
- a(1) = 1; a(n) = Sum_{k=1..n} a(ceiling((n-1)/k)).at n=38A290845