15130
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 10
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 16
- Divisor Sum
- 29160
- Proper Divisor Sum (Aliquot Sum)
- 14030
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 5632
- Möbius Function
- 1
- Radical
- 15130
- Omega Function (Ω)
- 4
- Little Omega Function (ω)
- 4
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
- yes
- Narcissistic Number
- no
- Collatz Steps
- 40
- 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
- Generalized Fibonacci numbers: a(n) = a(n-1) + 9*a(n-2).at n=8A015445
- a(n) = Sum_{i=1..floor((n+2)/4)} a(2i-1)*a(n-2i+1), with a(1)=a(2)=1 and a(3)=5.at n=13A024951
- Number of partitions of n with equal number of parts congruent to each of 1 and 4 (mod 5).at n=49A035558
- Number of partitions in parts not of the form 23k, 23k+3 or 23k-3. Also number of partitions with at most 2 parts of size 1 and differences between parts at distance 10 are greater than 1.at n=39A035991
- Number of graphical partitions of simple Eulerian graphs (partitions given by the degrees of vertices of simple (no loops or multiple edges) graphs having only vertices of even degrees) having n edges.at n=47A069831
- a(n) = Lucas(4n) + 3, or 5*Fibonacci(2n-1)*Fibonacci(2n+1).at n=5A081076
- Smallest squarefree integer k such that Q(sqrt(k)) has class number n.at n=31A081363
- Main diagonal of generalized Fibonacci array A083856.at n=9A083859
- Total number of palindromic primes in base 8 below 8^n.at n=10A117785
- Total number of palindromic primes in base 8 below 8^n.at n=11A117785
- Numbers such that the two adjacent integers are a perfect square and a prime.at n=46A163492
- Beach-Williams Pell numbers of type k^2 + 1.at n=15A212082
- a(n) is the number m such that f(sqrt(n)) is in the field Q(sqrt(m)), where f(x) is defined from the continued fraction x = [c(0),c(1),...] as [c(0)+2, c(1)+2,...].at n=40A229958
- Numbers whose square is a fourth power plus a prime.at n=21A236767
- a(n) = 9*n^2 + 1.at n=41A247792
- Numbers k that are the product of four distinct primes such that x^2+y^2 = k has integer solutions.at n=21A248712
- a(n) = (n + 1)*(6*n^2 + 15*n + 4)/2.at n=16A269232
- Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 81", based on the 5-celled von Neumann neighborhood.at n=27A270100
- Numbers of the form m^2 + 1 that can be expressed in more than one way as j^2 + k^2 with j > k > 1.at n=20A299708
- Numbers of the form m^2 + 1 that can be expressed in more than one way as j^2 + k^2 with j > k > 1 and gcd(j,k) = 1.at n=7A300166