12687
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 24
- Digital Root
- 6
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 16920
- Proper Divisor Sum (Aliquot Sum)
- 4233
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 8456
- Möbius Function
- 1
- Radical
- 12687
- 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
- no
- Odd
- yes
Appears in sequences
- Fibonacci sequence beginning 3, 11.at n=16A022123
- Number of dissimilar ternary squarefree words of length n+1.at n=31A060688
- Round(1000*x), where x is the solution to x = 3^(n-x).at n=15A103537
- Numbers k such that sigma(k) plus the k-th prime is a triangular number.at n=33A115907
- G.f.: A(x) = 1/(1 - x*B(x^3)), where B(x) = Sum_{n>=0} a(n)^3*x^n is the g.f. of A121652.at n=25A121653
- A trisection of A121653; a(n) = A121653(3*n+1) = A121652(3*n+1)^(1/3).at n=8A121655
- Number of strings of numbers x(i=1..5) in 0..n with sum i*x(i)^2 equal to n*25.at n=40A184444
- Irregular triangular array read by rows. T(n,k) is the number of weakly connected relations on n labeled nodes with k arcs. (n>=0, 0<=k<=n^2).at n=26A217563
- At stage 1, start with a unit equilateral triangle. At each successive stage add 3*(n-1) new triangles around outside with vertex-to-vertex contacts. Sequence gives number of triangles at n-th stage.at n=31A269064
- Number of partitions of n with up to ten distinct kinds of 1.at n=15A320697
- Number of partitions of n into 6 distinct and relatively prime parts.at n=54A341870
- Least k such that the k-th maximal antirun of prime numbers > 3 has length n. Position of first appearance of n in A027833. The sequence ends if no such antirun exists.at n=51A373401
- Expansion of e.g.f. 1/(1 - 2 * arcsin(x))^(1/2).at n=6A385376