8516
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 20
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 6
- Divisor Sum
- 14910
- Proper Divisor Sum (Aliquot Sum)
- 6394
- 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
- 4256
- Möbius Function
- 0
- Radical
- 4258
- Omega Function (Ω)
- 3
- 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
- 127
- 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
- Coordination sequence for alpha-Mn, Position Mn4.at n=24A009953
- Sum of (Gaussian) q-binomial coefficients for q=-2.at n=7A015152
- Numbers k such that the continued fraction for sqrt(k) has period 82.at n=19A020421
- a(n) = least m such that if r and s in {1/1, 1/3, 1/5, ..., 1/(2n-1)} satisfy r < s, then r < k/m < (k+3)/m < s for some integer k.at n=34A024844
- Numbers k such that the continued fraction for sqrt(k) has even period and if the last term of the periodic part is deleted the central term is 46.at n=41A031544
- Number of free n-ominoes with cell centers determining n-2 space (proper dimension n-2).at n=8A036364
- Triangle T(n,d) = number of distinct d-dimensional polyominoes (or polycubes) with n cells (0 < d < n).at n=53A049429
- Triangle read by rows: T(n,d) is the number of distinct properly d-dimensional polyominoes (or polycubes) with n cells (n >= 1, d >= 0).at n=64A049430
- a(n) = (9n^2 + 9n + 4)/2.at n=43A062123
- a(n) = (p^2 - p + 2)/2 for p = prime(n); number of squares modulo p^2.at n=31A072205
- Number of permutations satisfying -k<=p(i)-i<=r and p(i)-i not in I, i=1..n, with k=3, r=3, I={-1,0,2}.at n=19A079987
- a(n) = Sum_{d|n} d*binomial(n/d+d-2,d-1).at n=51A157020
- Irregular triangle in which row n has the values of k>n such that Sum_{i=n..k} i^2 is a square.at n=60A184763
- Number of 0..n arrays x(0..8) of 9 elements with zero 4th differences.at n=42A200445
- Number of idempotent 4 X 4 0..n matrices of rank 1.at n=7A224526
- Numbers k such that k^3 - b2 is a triangular number (A000217), where b2 is the largest square less than k^3.at n=26A233401
- a(n) gives the position of -n in the sequence (or tree) S generated in order by these rules: 0 is in S; if x is in S then x + 1 is in S; if nonzero x is in S then 1/x is in S; if x is in S, then i*x is in S; where duplicates are deleted as they occur.at n=10A233695
- Positions of integers in the sequence (or tree) S generated in order by these rules: 0 is in S; if x is in S then x + 1 is in S; if nonzero x is in S then 1/x is in S; if x is in S, then i*x is in S; where duplicates are deleted as they occur.at n=24A233696
- Number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 157", based on the 5-celled von Neumann neighborhood.at n=47A270329
- Number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 389", based on the 5-celled von Neumann neighborhood.at n=49A271594