6616
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 19
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 12420
- Proper Divisor Sum (Aliquot Sum)
- 5804
- 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
- 3304
- Möbius Function
- 0
- Radical
- 1654
- Omega Function (Ω)
- 4
- 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
- yes
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 44
- 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
- Number of switching networks (see Harrison reference for precise definition).at n=2A000826
- a(n) = a(n-1) + 7*a(n-2), a(0)=0, a(1)=1.at n=9A015442
- Cycle class sequence c(2n) (the number of true cycles of length 2n in which a certain node is included) for zeolite AFG = Afghanite (Na2,Ca,K2)12[Al24Si24O96] starting with a T2 atom.at n=5A018953
- 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 19.at n=40A031517
- T(n,n-3), array T as in A038792.at n=34A038793
- Numerators of continued fraction convergents to sqrt(614).at n=7A042178
- Numbers having three 6's in base 10.at n=13A043515
- Composite numbers not ending in zero that yield a prime when turned upside down.at n=37A048889
- Partial sums of A001157: Sum_{j=1..n} sigma_2(j).at n=24A064602
- Braided power sequence: A065692 is b(n+1) = 3*b(n) + 2*d(n) - c(n), this is c(n+1) = 3*c(n) + 2*b(n) - d(n) and A065694 is d(n+1) = 3*d(n) + 2*c(n) - b(n), starting with b(0) = 0, c(0) = 1 and d(0) = 2.at n=6A065693
- a(n) = x is the smallest number such that gcd(prime(x)-1,x-1) = n.at n=48A084315
- Numbers k such that k*k! + 1 is prime.at n=18A090703
- Triangular matrix, read by rows, equal to the matrix square of A102225, such that the first differences of row k forms row (k+1) of A102225.at n=32A102228
- Matrix square of triangle A104980.at n=22A104988
- Numbers k such that k*(k+8) gives the concatenation of two numbers m and m+2.at n=1A116305
- Triangle read by rows: T(n,m) is the number of cyclic permutations of [n] in which m of successive numbers add to a prime. 0<=m<=n, read by rows n>=0.at n=62A132178
- Number of (directed) Hamiltonian paths in the n-ladder graph.at n=57A137882
- Numbers k such that A120292(k) is composite.at n=35A141779
- 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, 0), (-1, 0, 1), (-1, 1, -1), (1, -1, 0), (1, 1, 0)}.at n=8A149138
- Square array, read by antidiagonals, where row n+1 is generated from row n by first removing terms in row n at positions 0 and {(m+1)*(m+2)/2-2, m>0} and then taking partial sums, starting with all 1's in row 0.at n=39A156628