11806
domain: N
Properties
Digital Properties
- Digit Count
- 5
- 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
- 17712
- Proper Divisor Sum (Aliquot Sum)
- 5906
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 5902
- Möbius Function
- 1
- Radical
- 11806
- 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
- 99
- 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
- a(n) = floor(n(n-1)(n-2)(n-3)/18).at n=23A011928
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 100 ones.at n=0A031868
- Numbers whose set of base-14 digits is {3,4}.at n=27A032838
- 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), (0, 0, 1), (1, 0, -1), (1, 1, 1)}.at n=7A150805
- Number of slanted n X 4 (i=1..n) X (j=i..4+i-1) 1..4 arrays with all 1s connected, all 2s connected, all 3s connected, all 4s connected, 1 in the upper left corner, 2 in the upper right corner, 3 in the lower left corner, 4 in the lower right corner, and with no element having more than 2 neighbors with the same value.at n=34A165378
- Partial sums of A068148.at n=24A178137
- First occurrence of n consecutive n's in the decimal expansion of E.at n=3A224828
- Integers k such that (k^2 + (k+1)^2) has no square proper substring.at n=62A238903
- Number of isosceles triangles, distinct up to congruence, on a centered hexagonal grid of size n.at n=45A241237
- Expansion of Product_{k>=1} (1 + x^k)^(2*k-1)!!.at n=6A305869
- A self-"read and extend" sequence built following the rules given in the Comments section.at n=65A316749
- a(n) = Sum_{1 <= x_1 <= x_2 <= x_3 <= x_4 <= x_5 <= x_6 <= x_7 <= n} gcd(x_1, x_2, x_3 , x_4, x_5, x_6, x_7, n).at n=9A343521
- For 1<=x<=n, 1<=y<=n, write gcd(x,y) = u*x+v*y with u,v minimal; a(n) = sum of the values of |u|.at n=49A345432
- a(n) = number of subsets of {1, 2, ..., n} that represent the first k divisors of m for some positive integers m and 1 <= k <= A000005(m).at n=29A378314
- a(n) = Sum_{k=0..n} 8^k * binomial(2*n+1,n-k).at n=4A386957