8809
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 25
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 9216
- Proper Divisor Sum (Aliquot Sum)
- 407
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 8404
- Möbius Function
- 1
- Radical
- 8809
- Omega Function (Ω)
- 2
- 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
- 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
- 78
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- yes
- 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
- no
- Odd
- yes
Appears in sequences
- a(n) = s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n+1-k), where k = [ (n+1)/2 ], s = (F(2), F(3), ...), t = (primes).at n=19A024597
- a(n) = s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n-k+1), where k = [ n/2 ], s = (F(2), F(3), F(4), ...), t = (primes).at n=18A025111
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 78 ones.at n=3A031846
- Numbers k such that 275*2^k + 1 is prime.at n=23A053354
- Integers n > 1997 such that the 'Reverse and Add!' trajectory of n joins the trajectory of 1997.at n=13A063055
- Numbers k such that sigma(k) and sigma(k+1) are nontrivial powers (A065496).at n=9A065522
- Numbers k such that k*(k+9) gives the concatenation of two numbers m and m-5.at n=1A116258
- Retrograde trajectory of 4 under map k -> A094077(k).at n=51A117150
- Number of permutations in S_n avoiding {bar 1}432 (i.e., every occurrence of 432 is contained in an occurrence of a 1432).at n=8A137533
- Numbers n such that Mordell's equation y^2 = x^3 + n has exactly 10 integral solutions.at n=40A179153
- The (10^n)-th lucky number.at n=3A181382
- Let f(m) = number of steps needed to reach a Harshad number when the map k->A062028(l) is iterated starting at m; a(n) = smallest m such that f(m) = n.at n=65A181664
- Number of 2 X 2 matrices with all elements in {1,2,...,n} and determinant in {-1,0,1}.at n=37A209994
- Number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 299", based on the 5-celled von Neumann neighborhood.at n=49A271152
- Numbers n such that the decimal number concat(3,n) is a square.at n=31A273358
- Expansion of 1/(1 - x*Product_{k>=1} 1/(1 + x^k)).at n=57A299208
- Number of total dominating sets in the n-antiprism graph.at n=6A302760
- O.g.f. A(x) satisfies: [x^n] 1/(1-x)^(n^3) / exp( n^2*A(x) ) = 0 for n >= 1.at n=3A319836
- Where the zeros in A123066 occur.at n=11A321962
- Number of partitions of the (n+2)-multiset {0,...,0,1,2} with n 0's into distinct multisets.at n=27A346822