8900
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 17
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 18
- Divisor Sum
- 19530
- Proper Divisor Sum (Aliquot Sum)
- 10630
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 3520
- Möbius Function
- 0
- Radical
- 890
- Omega Function (Ω)
- 5
- 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
- 140
- 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
- Number of n-input 3-output switching networks under action of S(n) and complementing group C(2,3) on inputs and outputs.at n=2A000860
- If F(n) is the n-th Fibonacci number, then a(2n) = (F(2n+1) + F(n+2))/2 and a(2n+1) = (F(2n+2) + F(n+1))/2.at n=20A001224
- a(n) = Sum_{0<=j<=i<=n} A027144(i, j).at n=9A027153
- a(n) = (Fibonacci(2*n)-(-1)^n*Fibonacci(n))/2.at n=11A049602
- Number of positive rational knots with 2n+1 crossings.at n=10A051450
- Number of distinct ways to tile a 2 X n rectangle with dominoes (solutions are identified if they are rotations or reflections of each other).at n=20A060312
- Number of incongruent ways to tile a 3 X 2n room with 1x2 Tatami mats. At most 3 Tatami mats may meet at a point.at n=20A068928
- a(n)=floor{square((1*n^0+1*n^1+2*n^2+4*n^3)/(1*n^0+2*n^1+1*n^2))}.at n=24A086863
- Numbers that reach the fixed point 89 under iteration of f(x) = reverse(x) - maxdigit(x).at n=10A097155
- Iccanobirt numbers (1 of 15): a(n) = a(n-1) + a(n-2) + R(a(n-3)), where R is the digit reversal function A004086.at n=17A102111
- Duplicate of A001224.at n=21A102526
- a(n) = 2*a(n-1) - a(n-2) + 2*(prime(n+1)-prime(n)); a(1) = 2, a(2) = 3.at n=46A122263
- a(n) = n^4 - n^3 - n^2.at n=10A132998
- a(n) = n*n in the arithmetic where when digits are to be added they are multiplied, and when they are to be multiplied they are added.at n=45A169921
- Sum of a positive square and a positive cube in at least three ways.at n=16A171385
- Numbers k such that Mordell's equation y^2 = x^3 + k has exactly 24 integral solutions.at n=1A179161
- Number of n X n binary arrays without the pattern 0 0 1 diagonally, antidiagonally or horizontally.at n=3A189257
- Number of nX4 binary arrays without the pattern 0 0 1 diagonally, antidiagonally or horizontally.at n=3A189259
- T(n,k)=Number of nXk binary arrays without the pattern 0 0 1 diagonally, antidiagonally or horizontally.at n=24A189264
- Number of 4Xn binary arrays without the pattern 0 0 1 diagonally, antidiagonally or horizontally.at n=3A189266