12636
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
- 3
Divisibility
- Divisor Count
- 36
- Divisor Sum
- 35672
- Proper Divisor Sum (Aliquot Sum)
- 23036
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 3888
- Möbius Function
- 0
- Radical
- 78
- Omega Function (Ω)
- 8
- 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
- yes
- Harshad Number
- yes
- Narcissistic Number
- no
- Collatz Steps
- 125
- 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
- yes
- Odd
- no
Appears in sequences
- a(n) = T(2n,n-1), where T is the array defined in A026105.at n=6A026115
- a(n) = (n+1)*(14*n^3+13*n^2+6*n+1).at n=5A027850
- Starting from generation 7 add previous and next term yielding generation 8.at n=25A048454
- 19-gonal (or enneadecagonal) numbers: n(17n-15)/2.at n=39A051871
- 22-gonal numbers: a(n) = n*(10*n-9).at n=36A051874
- Number of degree-n permutations of order dividing 6.at n=8A053496
- Numbers k such that sigma(x) = k has exactly 8 solutions.at n=29A060664
- a(n) = 2 * 3^(n-2)*n*(1+2*n).at n=6A062189
- Product(n/k - k) where the product is over the divisors k of n and where 1 <= k <= sqrt(n).at n=39A068333
- Numbers k such that the sum of the digits of k equals the sum of the prime divisors of k.at n=42A070275
- Numbers k such that iterating phi(sigma(k)-phi(k)) starting from k leads to the fixed point 8064.at n=20A077096
- Number of points of self-intersection of the path of a billiard ball traveling at a 45-degree angle on a prime(n) X prime(n+1) billiard table. Also equal to 1/2 the number of the lattice points lying within a prime(n) X prime(n+1) rectangle.at n=36A099407
- Antidiagonal sums of triangle A099605, in which row n equals the inverse binomial transform of column n of the triangle A034870 of even-indexed rows of Pascal's triangle.at n=12A099607
- Smallest n-aspiring number. That is, a(n) = smallest k such that s^(n)(k) is perfect but s^(n-1)(k) is not, where s(k) is the sum of the aliquot parts of k and s^(i) means iterate s i times.at n=16A099771
- a(n) = smallest possible (product of b(k)'s + product of c(k)'s), where the positive integers <= n are partitioned somehow into {b(k)} and {c(k)}.at n=11A127180
- Triangle read by rows, a generalization of the Eulerian numbers based on Nielsen's generalized polylogarithm (case m = 2).at n=35A142249
- Triangle T(n, k, m) = (m*(n-k) + 1)*T(n-1, k-1, m) + (m*k + 1)*T(n-1, k, m) - m*f(n,k)*T(n-2, k-1, m) with T(n, 0, m) = T(n, n, m) = 1, f(n, k) = k if k <= floor(n/2) otherwise n-k, and m = 2, read by rows.at n=24A157211
- a(n) = 361*n + 1.at n=34A158310
- Numbers k which are concatenations k=x//y such that x^2 + y^2 - x*y = k.at n=22A162556
- a(n) = binomial(n+1,2)*6^2.at n=26A162940