15308
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 17
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 12
- Divisor Sum
- 27720
- Proper Divisor Sum (Aliquot Sum)
- 12412
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 7392
- Möbius Function
- 0
- Radical
- 7654
- 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
- 84
- 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) = Sum_{k=0..2n} (k+1) * A027082(n, 2n-k).at n=8A027107
- Base-7 palindromes that start with 6.at n=34A043020
- Numbers whose base-3 representation contains exactly one 0 and no 1's.at n=29A044970
- Numbers k such that k^8 == 1 (mod 9^3).at n=41A056084
- a(n) = n*3^n - 1.at n=6A060352
- a(1) = 1; a(n+1) = a(n) + (largest square <= a(n)).at n=16A060984
- Least k such that k*10^n-9, k*10^n-7, k*10^n-3 and k*10^n-1 are all prime.at n=7A064432
- Duplicate of A064432.at n=7A064972
- n*10^7-1, n*10^7-3, n*10^7-7 and n*10^7-9 are all prime.at n=0A064982
- Floor[ concatenation of n+4, n+3, n+2, n+1 and n divided by 5].at n=3A075006
- Least common multiple of prime(n+1)-1 and prime(n)-1.at n=39A083554
- Convoluted convolved Fibonacci numbers G_j^(6).at n=10A089093
- Number of points of self-intersection of the path of a billiard ball traveling at a 45-degree angle on a prime(n) X prime(n+1) billiard table. Also equal to 1/2 the number of the lattice points lying within a prime(n) X prime(n+1) rectangle.at n=39A099407
- a(n) = prime(n) * 3^prime(n) - 1.at n=3A100688
- Poincaré series [or Poincare series] P(C_{3,2}(0); t).at n=29A124636
- a(n) = 729*n - 1.at n=20A158395
- Recurrence sequence derived from the digits of the square root of 5 after its decimal point.at n=18A189893
- Number of length n arrays of permutations of 0..n-1 with each element moved by -2 to 2 places and exactly one more element moved upwards than downwards.at n=13A263758
- Expansion of g.f.: (1 + x - 2*x^2 + 2*x^4)/((1-x)*(1-3*x^2)).at n=17A358027