15845
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 23
- Digital Root
- 5
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 19020
- Proper Divisor Sum (Aliquot Sum)
- 3175
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 12672
- Möbius Function
- 1
- Radical
- 15845
- Omega Function (Ω)
- 2
- Little Omega Function (ω)
- 2
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
- yes
- 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
- Nearest integer to Gamma(n + 2/9)/Gamma(2/9).at n=9A020023
- a(n) = ceiling of Gamma(n + 2/9)/Gamma(2/9).at n=9A020113
- Numbers n such that n | 9^n + 7^n + 5^n + 3^n +1.at n=9A057831
- Number of permutations of length n which avoid the patterns 321, 12354.at n=14A116846
- Expansion of (chi(-x) * chi(-x^19))^(-2) in powers of x where chi() is a Ramanujan theta function.at n=30A134004
- Starting values that produce a larger juggler number than smaller starting values.at n=12A143742
- Numbers n such that 10^n - 51 is prime.at n=7A178429
- Number of strings of numbers x(i=1..6) in 0..n with sum i^4*x(i) equal to 1296*n.at n=27A184352
- Irregular array read by rows. a(n) is the largest element in the primitive Collatz-like 3x-k cycle associated with A226623(n).at n=13A226624
- Number of partitions of n having depth 2; see Comments.at n=41A237750
- Number of reduced normal play partisan games born on or before day n.at n=4A260969
- Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 478", based on the 5-celled von Neumann neighborhood.at n=32A272453