7698
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 30
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 15408
- Proper Divisor Sum (Aliquot Sum)
- 7710
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- yes
Derived Values
- Euler's Totient
- 2564
- Möbius Function
- -1
- Radical
- 7698
- Omega Function (Ω)
- 3
- 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
- yes
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 132
- 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
- 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 86.at n=20A031584
- Positive numbers having the same set of digits in base 7 and base 9.at n=34A037439
- Number of ways to place 2n nonattacking kings on a 4 X 2n chessboard.at n=4A061593
- Matrix inverse of triangle A099602, read by rows, where row n of A099602 equals the inverse binomial transform of column n of the triangle of trinomial coefficients (A027907).at n=71A104495
- a(n) = n * Sum_{d|n} binomial(n,d)/gcd(n,d).at n=13A105862
- For each positive integer n, consider the ternary sequence given initially by x(i) = 0 if 1 <= i < n, x(n) = 1; and thereafter determined by the quadratic recurrence x(i) = x(i-1) + x(i-n)^2 mod 3. Define a(n) to be the smallest positive integer N for which x(N+i) = x(i) for all sufficiently large i.at n=54A112683
- Numbers k such that phi(k) + prime(k) is a triangular number.at n=31A115908
- Numbers n for which 12n+1, 12n+5, 12n+7 and 12n+11 are primes.at n=37A123985
- Limiting values for category table A125697.at n=5A125701
- G.f.: A(x) = F(x*G(x)^3) = F(G(x)-1) where F(x) = G(x/F(x)) = 1 + x*F(x)^2 is the g.f. of A000108 (Catalan) and G(x) = F(x*G(x)) = 1 + x*G(x)^3 is the g.f. of A001764.at n=6A153296
- The first of a pair of sequences A and B with property that all the differences |a_i - b_j| are distinct - for precise definition see Comments lines.at n=42A169677
- Number of ways to place 5n nonattacking kings on a 10 X 2n chessboard.at n=1A173783
- Riordan array ( (1/(1-x))^m , x*A000108(x) ), m =4.at n=59A185945
- Triangle T(n,k) = coefficient of x^n in expansion of ((1-sqrt(1-4*x))/((1-x)*2))^k = sum(n>=k, T(n,k) * x^n).at n=48A200965
- Fibonacci + Goldbach: a(1)=6, a(2)=8 and for n>=3, a(n)=g(a(n-1)) + g(a(n-2)), where for m>=3, g(2*m) is the maximal prime p < 2*m such that 2*m - p is prime.at n=20A216275
- Denominators of Bernoulli numbers which are congruent to 3 (mod 9).at n=39A219543
- Bernoulli denominators with 8 divisors in increasing order (without repetitions).at n=34A219742
- Number of binary arrays indicating the locations of trailing edge maxima of a random length-n 0..6 array extended with zeros and convolved with 1,3,3,1.at n=18A222025
- Generalized Markoff numbers: largest of 7-tuple of positive numbers a, b, c, d, e, f, g satisfying the Markoff(7) equation a^2+b^2+c^2+d^2+e^2+f^2+g^2 = 3abcdefg.at n=25A227211
- Number of partitions p of n such that (maximal multiplicity of the parts of p) >= (maximal part of p).at n=40A240313