12786
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
- 8
- Divisor Sum
- 25584
- Proper Divisor Sum (Aliquot Sum)
- 12798
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- yes
Derived Values
- Euler's Totient
- 4260
- Möbius Function
- -1
- Radical
- 12786
- Omega Function (Ω)
- 3
- Little Omega Function (ω)
- 3
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
- 169
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- 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(1)= 10000, a(2)= 10000; for n>2, a(n)= ( a(n-2) + a(n-1) ) (mod 20000).at n=27A096973
- Number of ways you can split the set of the first n primes into two proper subsets of which the sum of one is thrice the sum of the other.at n=24A113044
- Expansion of (eta(q^4) * eta(q^12) / (eta(q) * eta(q^3)))^2 in powers of q.at n=17A123647
- Expansion of c(5x^2)/(1-x*c(5x^2)), where c(x) is the g.f. of A000108.at n=8A128387
- G.f.: 5/(2 + 3*sqrt(1-20*x)).at n=4A130977
- Number of emergent parts in all partitions of n.at n=34A182699
- Square array A(n,k) by antidiagonals. A(n,k) is the number of length 2n k-ary words (n,k>=0) that can be built by repeatedly inserting doublets into the initially empty word.at n=59A183135
- Number of nondecreasing arrangements of n numbers in -3..3 with sum zero and sum of squares less than n*12/3.at n=26A183929
- Number of -2..2 arrays x(i) of n+1 elements i=1..n+1 with x(i)+x(j), x(i+1)+x(j+1), -(x(i)+x(j+1)), and -(x(i+1)+x(j)) having two or three distinct values for every i<=n and j<=n.at n=9A211461
- Number of (w,x,y,z) with all terms in {1,...,n} and w > harmonic mean of {x,y,z}.at n=12A212105
- Smallest number k such that sopf(k)/digsum(k) = prime(n) where sopf(k) is the sum of the distinct primes dividing k and digsum(k) the sum of digits of k.at n=23A241049
- Ascending list of base-60 happy numbers written in base 10.at n=34A318235
- Number of integer partitions of n containing all prime indices of their parts.at n=41A324753
- a(n) = Sum_{k=0..n} phi(k^2 + 1), where phi is the Euler totient function (A000010).at n=38A333170
- Sixth Lie-Betti number of a path graph on n vertices.at n=11A364946
- Irregular table read by rows: T(n,k) is the number of k-sided polygons, for n>=1 and k>=3, in a hexagon when straight line segments connect the n-1 points between each corner that divide each edge into n equal parts to the n-1 points on the edge on the opposite side of the hexagon.at n=47A367665
- Consecutive states of the linear congruential pseudo-random number generator (1741*s + 2731) mod 12960 when started at s=1.at n=35A385335