8670
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 21
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 24
- Divisor Sum
- 22104
- Proper Divisor Sum (Aliquot Sum)
- 13434
- 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
- 2176
- Möbius Function
- 0
- Radical
- 510
- Omega Function (Ω)
- 5
- 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
- no
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 65
- 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
- Numbers k such that k!! - 1 is prime.at n=18A007749
- a(n) = T(n, n+4), T given by A027052.at n=9A027055
- a(n) = A027052(n, 2n-9).at n=8A027065
- Number of 2n-bead balanced binary strings of fundamental period 2n, rotationally equivalent to reverse, complement and reversed complement.at n=17A045665
- Local ranks of terms of A057122.at n=46A057124
- Let r, s, t be three permutations of the set {1,2,3,..,n}; a(n) = value of Sum_{i=1..n} r(i)*s(i)*t(i), with r={1,2,3,..,n}; s={n,n-1,..,1} and t={n,n-2,n-4,...,1,...,n-3,n-1}.at n=17A070893
- Expansion of (1+x+x^2)/((1+x^2)*(1+x)^4*(1-x)^5).at n=34A082290
- E.g.f.: (x^2/2-2*x+3)*tan(x/2+Pi/4)-3*x^3-x-3.at n=9A131611
- Principal number of K. Saito for tree of type E_n.at n=9A131656
- Trajectory of 7 under the map m -> A082010(m).at n=44A152199
- Number of cubic equations ax^3 + bx^2 + cx + d = 0 with integer coefficients |a|,|b|,|c|,|d| <= n, a <> 0, having three real roots, of which at least two are equal.at n=33A155192
- Numbers of the form n = r*s = (r+s)*t with gcd(r+s,t) = 1.at n=38A163188
- Number of right triangles on an (n+1) X 3 grid.at n=35A189807
- a(n) = 4^n*(n+1)*(8*n^2+32*n+33)*P(3/2,n)/(3*P(4,n)) where P(a,n) is the Pochhammer rising factorial.at n=4A217946
- Triangle numbers: m = a*b*c such that the integers a,b,c are the sides of a triangle with integer area.at n=29A218243
- Primitive triangle numbers as defined in A218243.at n=20A218392
- Denominator of the rationals obtained from the e.g.f. D(1,x), a Debye function.at n=16A227540
- Pairs of Pythagorean numbers differing by 6.at n=23A228875
- Upper Pythagorean twins.at n=11A228877
- Numbers k such that 1 + k + k^3 + k^5 + k^7 + k^9 + ... + k^49 is prime.at n=43A244388