15039
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 18
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 22320
- Proper Divisor Sum (Aliquot Sum)
- 7281
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 10008
- Möbius Function
- 0
- Radical
- 1671
- Omega Function (Ω)
- 4
- 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
- 270
- 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
- no
- Odd
- yes
Appears in sequences
- Landau's approximation to population of x^2 + y^2 <= 2^n.at n=16A000690
- Numbers whose base-4 representation contains exactly three 2's and four 3's.at n=15A045152
- a(n) = 12 + floor((1 + Sum_{j=1..n-1} a(j))/4).at n=32A120169
- Numbers k such that binomial(5k, k) - 1 is prime.at n=15A125242
- a(n) = numerator of Sum_{k>=1} floor(n/k)/2^k.at n=11A178965
- Largest possible side length for a perfect squared square of order n; or 0 if no such square exists.at n=35A217149
- Irregular array read by rows: T(n,k) = number of r_{n,k}-cores associated with A233332(n,k), for n>=2, 1<=k<=floor(n/2), explained below.at n=44A233330
- Indices of even terms in A249064.at n=41A249557
- n such that (1+2*7^n)/3 is prime.at n=13A263718
- Decimal representation of the x-axis, from the origin to the right edge, of the n-th stage of growth of the two-dimensional cellular automaton defined by "Rule 99", based on the 5-celled von Neumann neighborhood.at n=13A278873
- Decimal representation of the x-axis, from the origin to the right edge, of the n-th stage of growth of the two-dimensional cellular automaton defined by "Rule 107", based on the 5-celled von Neumann neighborhood.at n=13A278901
- a(n) = a(n-1) + a(n-2) + a([2n/3]), where a(0) = 1, a(1) = 1, a(2) = 1.at n=18A298342
- a(n) is (apparently) the largest number k whose Collatz (or '3x+1') trajectory includes the number k + n.at n=34A303876
- Numbers k such that A307437(k) is divisible by 3.at n=25A342037
- Number of growing self-avoiding walks of length n on a half-infinite strip of height 7 with a trapped endpoint.at n=11A374305
- a(n) is the maximum number of strong sub-tournaments in an n-tournament.at n=14A386875