6809
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 23
- Digital Root
- 5
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 7440
- Proper Divisor Sum (Aliquot Sum)
- 631
- 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
- 6180
- Möbius Function
- 1
- Radical
- 6809
- 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
- 181
- 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
- Discriminants of totally real quartic fields.at n=26A023680
- Positive numbers having the same set of digits in base 6 and base 9.at n=32A037436
- Numerators of continued fraction convergents to sqrt(583).at n=4A042116
- Denominators of continued fraction convergents to sqrt(941).at n=9A042821
- Numbers whose base-4 representation contains exactly three 1's and four 2's.at n=13A045104
- Composite numbers not ending in zero that yield a prime when turned upside down.at n=41A048889
- Total number of elements in all primitive subsets of the integers 1 to n.at n=16A087077
- a(n) equals the (n*(n+1)/2)-th partial sum of the self-convolution cube of A010054, which has the g.f.: Sum_{k>=0} x^(k*(k+1)/2).at n=23A109414
- a(n) = 2^n + 3^n - n.at n=8A120848
- Complete list of discriminants of definite Eichler orders with class number 2.at n=40A143748
- Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 1), (-1, 0, 0), (-1, 1, 1), (1, -1, -1), (1, 1, 0)}.at n=8A149111
- Expansion of (1+62*x+564*x^2+1041*x^3+476*x^4+51*x^5+x^6)/(1-x)^7.at n=3A160817
- a(n) = 3*A022004(n) + 8.at n=26A163635
- a(n) = 5*n^2 - n + 1.at n=37A172043
- Numbers k such that 3^k (mod 2^k) is prime.at n=17A178995
- Number of permutations of 1..n with displacements restricted to {-5,-4,-2,0,1,3}.at n=11A189590
- Numbers k such that tau(k-1) = (tau(k))^2 = tau(k+1), where tau(k) = A000005(k) (number of divisors of k).at n=23A190266
- Number of ways to place 2 nonattacking kings on an n X n cylindrical chessboard.at n=10A194650
- Triangle of coefficients of polynomials v(n,x) jointly generated with A209583; see the Formula section.at n=50A209584
- Numbers n such that Q(sqrt(n)) has class number 9.at n=9A218041