6820
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 16
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 24
- Divisor Sum
- 16128
- Proper Divisor Sum (Aliquot Sum)
- 9308
- 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
- 2400
- Möbius Function
- 0
- Radical
- 3410
- 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
- 137
- 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 that are the sum of 8 positive 7th powers.at n=26A003375
- Numbers that are the sum of 5 nonzero 8th powers.at n=7A003383
- Numbers that are the sum of at most 5 nonzero 8th powers.at n=29A004878
- Numbers that are the sum of at most 6 nonzero 8th powers.at n=37A004879
- a(n) = floor(n*phi^15), where phi is the golden ratio, A001622.at n=5A004930
- a(n) = round(n*phi^15), where phi is the golden ratio, A001622.at n=5A004950
- Number of regions in regular n-gon with all diagonals drawn.at n=21A007678
- Number of Hamiltonian paths in a 5 X n grid starting in the lower left corner and ending in the lower right.at n=8A014585
- a(n) = (d(n)-r(n))/5, where d = A026049 and r is the periodic sequence with fundamental period (4,1,4,0,1).at n=42A026051
- Positions of the incrementally largest terms in the continued fraction expansion of zeta(3), offset 1 variant.at n=13A033167
- Number of nonempty subsets of {1,2,...,n} in which exactly 2/5 of the elements are <= n/3.at n=16A047199
- Number of nonempty subsets of {1,2,...,n} in which exactly 2/5 of the elements are <= (n-1)/3.at n=16A048011
- Number of nonempty subsets of {1,2,...,n} in which exactly 2/5 of the elements are <= (n-2)/3.at n=16A048022
- Iterated procedure 'composite k added to sum of its prime factors reaches a prime' yields 8 skipped primes.at n=41A050775
- Integer part of log(n^n)^(1 + log(1 + log(n))).at n=16A062449
- Integer part of log(n)^sqrt(n).at n=43A062463
- Numbers k such that phi(k) + 1 = x^2 and sigma(k) + 1 = y^2 for some x and y.at n=36A063532
- Numbers having exactly three prime gaps in their factorization.at n=40A073495
- a(n) = S1(n,3), where S1(n, t) = Sum_{k=0..n} (k^t * Sum_{j=0..k} binomial(n,j)).at n=5A089660
- Number of configurations of the 6 X 6 variant of Sam Loyd's sliding block 15-puzzle ("35-puzzle") that require a minimum of n moves to be reached, starting with the empty square in one of the corners.at n=10A090032