6406
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
- 4
- Divisor Sum
- 9612
- Proper Divisor Sum (Aliquot Sum)
- 3206
- 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
- 3202
- Möbius Function
- 1
- Radical
- 6406
- 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
- 62
- 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
- yes
- Odd
- no
Appears in sequences
- Number of permutations of length n with equal cycles.at n=7A005225
- Population of "Triangle" cellular automaton at n-th generation.at n=36A018189
- Numbers having period-4 6-digitized sequences.at n=37A031197
- 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 80.at n=1A031578
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 60 ones.at n=5A031828
- Trajectory of 1 under map n->21n+1 if n odd, n->n/2 if n even.at n=9A033967
- Trajectory of 3 under map n->21*n+1 if n odd, n->n/2 if n even.at n=16A037108
- a(n) = Sum_{k=1..n, m=1..k} T(m,k); array T as in A049828.at n=41A049830
- a(n+1) = a(n) converted to base 10 from base 16.at n=10A055987
- a(1)=1, then a(n)=2*a(n-1) if a(n-1) is prime, a(n)=a(n-1)+1 otherwise.at n=40A080735
- Row sums of triangle A086632.at n=6A086633
- Indices in A146326 where records occur.at n=35A146345
- 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), (0, 0, -1), (1, 0, 1)}.at n=8A149249
- Number of ways to place zero or more nonadjacent 1,0 1,1 2,0 2,1 3,0 4,0 polyhexes in any orientation on a planar nXnXn triangular grid.at n=5A155252
- A Chebyshev transform of the large Schroeder numbers A006318.at n=7A162543
- a(n) = n*(7*n + 11)/2 + 1.at n=42A198017
- Triangular array read by rows: T(n,k) is the number of n-permutations that have exactly k distinct cycle lengths.at n=14A218868
- Number of connected cyclic conjugacy classes of subgroups of the symmetric group.at n=51A218970
- Number of ordered triples (i,j,k) with i*j*k <= n and i,j,k >= 0.at n=44A226600
- Number of (n+1)X(n+1) 0..2 arrays with every element next to itself plus and minus one within the range 0..2 horizontally or antidiagonally, with no adjacent elements equal.at n=3A232581