15456
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 21
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 48
- Divisor Sum
- 48384
- Proper Divisor Sum (Aliquot Sum)
- 32928
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 4224
- Möbius Function
- 0
- Radical
- 966
- Omega Function (Ω)
- 8
- 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
- yes
- Harshad Number
- yes
- Narcissistic Number
- no
- Collatz Steps
- 27
- 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) = 7*a(n-1) - a(n-2) with a(0) = 0, a(1) = 1.at n=6A004187
- a(n) = floor(Fibonacci(n)/3).at n=24A004696
- Number of sum-free subsets of {1, ..., n}.at n=21A007865
- Rectangular array of numbers Fibonacci(m(n+1))/Fibonacci(m), m >= 1, n >= 0, read by downward antidiagonals.at n=41A028412
- Numbers n such that n divides the (right) concatenation of all numbers <= n written in base 13 (most significant digit on right).at n=19A029506
- Integers that appear as ratios of Fibonacci numbers F(kn)/F(k), but omitting Fibonacci numbers F(n)/F(1) and Lucas numbers F(2n)/F(n).at n=17A031122
- Numbers in which all pairs of consecutive base-7 digits differ by 3.at n=39A033078
- Expansion of (3 + x^2) / (1 - x)^4.at n=27A037237
- a(n) = Fibonacci(8n)/3.at n=3A049686
- Numbers k such that k | sigma_11(k).at n=31A055715
- Numbers k such that sigma (x) = k has exactly 11 solutions.at n=18A060678
- Table by antidiagonals of T(n,k)=n*T(n,k-1)-T(n,k-2) starting with T(n,1)=1.at n=72A073134
- Number of integers in {1, 2, ..., Fibonacci(n)} that are coprime to n.at n=23A074934
- a(1) = 1, a(n) = smallest number such that the concatenation of a(n-1) and a(n) is a cube.at n=2A082211
- 63-gonal numbers: a(n) = n*(61*n - 59)/2.at n=23A098140
- A Fibonacci convolution.at n=11A099483
- A Fibonacci convolution.at n=11A099484
- a(n) = A108994(n)*2/(n+2) for n>=0.at n=5A108995
- Numbers k such that sigma(k) and phi(k) are both palindromes.at n=7A113929
- Numbers k such that phi(k) + prime(k) is a triangular number.at n=41A115908