12686
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 23
- Digital Root
- 5
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 19032
- Proper Divisor Sum (Aliquot Sum)
- 6346
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 6342
- Möbius Function
- 1
- Radical
- 12686
- 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
- 55
- 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
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 60 ones.at n=33A031828
- Numbers k such that 1 + binomial(k,j) is prime for only 2 values of j (0 <= j <= k).at n=39A067317
- Let f(n) be 2n + POD(n) + 1 if n is even, otherwise 2n - POD(n) - 1, where POD(n) is the product of digits of n. Sequence gives smallest number requiring n iterations to reach a prime.at n=47A074808
- Number of planar n X n X n binary triangular grids symmetric under 120 degree rotation with no more than 3 ones in any 4 X 4 X 4 subtriangle.at n=4A153923
- Those positive integers n where, when written in binary, there are exactly k number of runs (of either 0's or 1's) each of exactly k length, for all k where 1<=k<=m, for some positive integer m.at n=18A175356
- a(n) = floor(e^e^(n/e^gamma)).at n=4A216756
- Number of binary strings of length n avoiding "squares" (that is, repeated blocks of the form xx) with |x| > 2.at n=16A229614
- Number of (n+1)X(n+1) 0..2 arrays colored with the difference of the maximum and minimum in each 2X2 subblock.at n=2A236047
- Number of (n+1)X(3+1) 0..2 arrays colored with the difference of the maximum and minimum in each 2X2 subblock.at n=2A236050
- T(n,k)=Number of (n+1)X(k+1) 0..2 arrays colored with the difference of the maximum and minimum in each 2X2 subblock.at n=12A236055
- Number of n X 4 nonnegative integer arrays with upper left 0 and lower right n+4-4 and value increasing by 0 or 1 with every step right or down.at n=6A252872
- Number of nX7 nonnegative integer arrays with upper left 0 and lower right n+7-4 and value increasing by 0 or 1 with every step right or down.at n=3A252875
- T(n,k) = Number of n X k nonnegative integer arrays with upper left 0 and lower right n+k-4 and value increasing by 0 or 1 with every step right or down.at n=48A252876
- T(n,k) = Number of n X k nonnegative integer arrays with upper left 0 and lower right n+k-4 and value increasing by 0 or 1 with every step right or down.at n=51A252876
- Pisot sequence T(3,16).at n=5A278681
- Number of separable partitions of n in which the number of distinct (repeatable) parts <= 6.at n=35A325715
- Numbers k such that A380459(k) has no divisors of the form p^p, while A003415(k) has such a divisor or is 0.at n=45A380474
- a(n) = Sum_{k=0..floor(n/3)} binomial(n,k) * binomial(n-2*k,k)^2.at n=10A383526
- Numbers k such that there is a smaller number m > 1 such that k*m equals the concatenation of digit-wise multiplication, keeping the leading digits of k when m has fewer digits.at n=37A392568