15129
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
- 2
Divisibility
- Divisor Count
- 9
- Divisor Sum
- 22399
- Proper Divisor Sum (Aliquot Sum)
- 7270
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 9840
- Möbius Function
- 0
- Radical
- 123
- 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
- yes
- 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
- 208
- 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
- yes
- Achilles Number
- no
- Perfect Power
- yes
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- a(n) = a(n-1) + a(n-2) - 2, a(0) = 4, a(1) = 3.at n=20A000211
- a(n) = n + n*(n-1)*(n-2)*(n-3)*(n-4).at n=9A001095
- Squares of Lucas numbers.at n=10A001254
- A Fielder sequence: a(n) = a(n-1) + a(n-3) + a(n-4), n >= 4.at n=20A001638
- Numbers of terms in expressions for coefficients of "Lovelock Lagrangians" (or "Gauss-Bonnet forms") in terms of Riemann-Christoffel curvature tensor and two of its contractions (viz., the Ricci curvature tensor and the Riemann curvature scalar) for n-dimensional differentiable manifolds having a general linear connection.at n=8A006372
- Number of restricted circular combinations.at n=18A006499
- Squares of odd Lucas numbers.at n=6A014730
- a(n) = (3*n)^2.at n=41A016766
- a(n) = (4n + 3)^2.at n=30A016838
- a(n) = (5*n + 3)^2.at n=24A016886
- a(n) = (6*n+3)^2.at n=20A016946
- a(n) = (7*n + 4)^2.at n=17A017030
- a(n) = (8n + 3)^2.at n=15A017102
- a(n) = (9*n + 6)^2.at n=13A017234
- a(n) = (10*n + 3)^2.at n=12A017306
- a(n) = (11*n + 2)^2.at n=11A017414
- a(n) = (12*n + 3)^2.at n=10A017558
- a(n) is the smallest square that is the sum of n distinct positive squares.at n=34A018936
- Smallest square containing n-th prime as substring.at n=35A029945
- Numbers with 9 divisors.at n=38A030627