6810
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 15
- Digital Root
- 6
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 16
- Divisor Sum
- 16416
- Proper Divisor Sum (Aliquot Sum)
- 9606
- 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
- 1808
- Möbius Function
- 1
- Radical
- 6810
- Omega Function (Ω)
- 4
- 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
- yes
- Narcissistic Number
- no
- Collatz Steps
- 62
- 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
- a(n) = s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n+1-k), where k=[ (n+1)/2 ], s = (natural numbers >= 2), t = (natural numbers >= 3).at n=39A024306
- a(n) = 2*(n+1) + 3*n + ... + (k+1)*(n+2-k), where k = floor(n/2).at n=39A024868
- a(n) = s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n-k+1), where k = floor( n/2 ), s = natural numbers >= 2, t = natural numbers >= 3.at n=38A024869
- a(n) = floor(2nd elementary symmetric function of Sum_{j=1..k} 1/j, k = 1,2,...,n).at n=34A025212
- Expansion of 1/((1-3x)(1-5x)(1-9x)(1-10x)).at n=3A028068
- Number of positive integers <= 2^n of form 3 x^2 + 7 y^2.at n=16A054164
- The sequence lambda(4,n), where lambda is defined in A055203. Number of ways of placing n identifiable positive intervals with a total of exactly four starting and/or finishing points.at n=5A059116
- Square array of lambda(k,n), where lambda is defined in A055203. Number of ways of placing n identifiable positive intervals with a total of exactly k starting and/or finishing points.at n=50A059117
- Variation of Boustrophedon transform applied to sequence 1,0,0,0,...: fill an array by diagonals in alternating directions - 'up' and 'down'. The first element of each diagonal after the first is 0. When 'going up', add to the previous element the elements of the row the new element is in. When 'going down', add to the previous element the elements of the column the new element is in. The final element of the n-th diagonal is a(n).at n=8A059219
- The array in A059219 read by antidiagonals in 'up' direction.at n=36A059220
- The array in A059219 read by antidiagonals in 'up' direction.at n=46A059220
- The array in A059219 read by antidiagonals in the direction in which it was constructed.at n=44A059235
- The array in A059219 read by antidiagonals in the direction in which it was constructed.at n=46A059235
- Triangle T(n,k), 0<=k<=n, giving coefficients when output sequence O_0, O_1, O_2, ... from transformation described in A059216 is expressed in terms of input sequence I_0, I_1, I_2, ...at n=44A059718
- Triangle T(n,k), 0<=k<=n, formed from coefficients when formula for n-th diagonal of triangle in A059718 is written as a sum of binomial coefficients.at n=37A059720
- Areas of integer Heronian triangles [prime(A068964(n)), prime(A068964(n)+1), A068965(n)].at n=3A068966
- Number of even non-cototients not exceeding 2^n.at n=15A072297
- A000041(n) - A000203(n).at n=30A086738
- Indices k where A057176(k) = 4.at n=18A086838
- Number of Ruth-Aaron numbers (with multiplicity) less than 10^n.at n=8A101805