12681
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 18
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 6
- Divisor Sum
- 18330
- Proper Divisor Sum (Aliquot Sum)
- 5649
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 8448
- Möbius Function
- 0
- Radical
- 4227
- Omega Function (Ω)
- 3
- 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
- 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
- no
- Odd
- yes
Appears in sequences
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 58 ones.at n=22A031826
- a(n) = 104*n + 9977.at n=26A126978
- Number of distinct means of nonempty subsets of {1,...,n}.at n=49A135342
- Number of nondecreasing arrangements of 4 nonzero numbers in -(n+2)..(n+2) with sum zero.at n=35A188334
- Number of (w,x,y,z) with all terms in {1,...,n} and w+x<2y+2z.at n=11A212562
- a(n) = Sum_{i=0..n} digsum_9(i)^3, where digsum_9(i) = A053830(i).at n=41A231686
- Number of palstars of length 2n over an alphabet of size 3.at n=6A246020
- a(n) = floor(1/(Pi - 2^(n+1)*sin(Pi/2^(n+1)))).at n=6A248347
- Number of vertices in an diagonal-edged (or diamond-shaped) checkerboard with width and height 2*n-1 (see Comments in A333434 for definition).at n=4A333459
- Odd numbers for which sigma(k) is congruent to 2 modulo 4 and the 3-adic valuation of k is one larger than the 3-adic valuation of sigma(k).at n=45A351534