13491
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
- 2
Divisibility
- Divisor Count
- 6
- Divisor Sum
- 19500
- Proper Divisor Sum (Aliquot Sum)
- 6009
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 8988
- Möbius Function
- 0
- Radical
- 4497
- 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
- 76
- 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
- Composite numbers k such that digits in k and in juxtaposition of prime factors of k are the same (apart from multiplicity).at n=33A035141
- Becomes prime after exactly 7 iterations of f(x) = sum of prime factors of x.at n=30A047826
- Members of 3-cycles of permutation A111273.at n=11A113701
- Number of (w,x,y,z) with all terms in {1,...,n} and w^2>=x*y*z.at n=17A212064
- a(1) = 1; for n>1, a(n) = smallest number > a(n-1) such that the pairwise differences of elements are distinct, and for 1<m<n, a(m) does not divide a(n).at n=56A256062
- a(n) is the number of ways to select an ordered pair of subsets of {2,...,n} such that each pair of elements from different subsets are relatively prime.at n=11A260185
- Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 598", based on the 5-celled von Neumann neighborhood.at n=38A273151
- Solution (a(n)) of the complementary equation in Comments.at n=39A298877
- Number of partitions of n with ten parts in which no part occurs more than twice.at n=32A320598
- Number of even-length integer partitions of n with integer alternating product.at n=46A347704
- Indices where the cumulative sum of sin(2k+1)^(2k+1) reaches a record high value.at n=33A387706