13473
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
- 8
- Divisor Sum
- 20000
- Proper Divisor Sum (Aliquot Sum)
- 6527
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 8964
- Möbius Function
- 0
- Radical
- 1497
- Omega Function (Ω)
- 4
- 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
- 138
- 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
- Conjecturally, number of infinitely-recurring prime patterns on n consecutive integers.at n=34A023192
- Ordered factorizations with one level of parentheses indexed by prime signatures. A050354(A025487).at n=35A050355
- Polynomial (1/3)*n^3 + (9/2)*n^2 + (85/6)*n - 2.at n=30A073775
- Let M be the matrix defined in A111490. Sequence gives the sum of the elements of the submatrices (from the upper left element): M(1,1); M(1,1)+M(1,2)+M(1,2)+M(2,2); M(1,1)+M(1,2)+M(1,3)+M(2,1)+M(2,2)+M(2,3)+M(3,1)+M(3,2)+M(3,3), etc.at n=37A123326
- Number of ways to place zero or more nonadjacent 1,0 1,1 2,0 2,2 3,0 3,2 polyhexes in any orientation on a planar nXnXn triangular grid.at n=6A155313
- Number of (w,x,y,z) with all terms in {1,...,n} and 2|w-x|=|x-y|+|y-z|.at n=27A212575
- Numbers generated by recursive procedure a(n) = nozero(a(n-1) * 3), in which the function nozero(x) removes all zeros from x, starting with a(1) = 1.at n=17A243845
- Triangle T(n,k), n>=0, 0<=k<=n, read by rows: row n is the inverse binomial transform of the n-th row of array A255961, which has the Euler transform of (j->j*k) in column k.at n=60A257673
- a(n) = A257673(2n,n).at n=5A257675
- Sum of the squares of the smaller parts of the partitions of 2n into two squarefree parts.at n=46A280320
- Number of compositions (ordered partitions) of n into tetrahedral (or triangular pyramidal) numbers (A000292).at n=30A282582
- Column k=5 of triangle A257673.at n=5A321950
- Odd numbers k such that sigma(k) + sigma(k+2) > 2*sigma(k+1); odd terms in A053228.at n=29A358395
- Expansion of e.g.f. (1/x) * Series_Reversion( x * exp(-x * (1 + x)^2) / (1 + x)^2 ).at n=4A380781