13238
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 17
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 19860
- Proper Divisor Sum (Aliquot Sum)
- 6622
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 6618
- Möbius Function
- 1
- Radical
- 13238
- 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
- 138
- 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
- yes
- Odd
- no
Appears in sequences
- a(n) = number of distinct values of Product_{i=1..r} x_i!*i!^x_i, where (x_1, ..., x_r) is an r-tuple of nonnegative integers with Sum_{i=1..r} i*x_i = n.at n=45A102465
- Number of compositions of n into 6 parts such that no two adjacent parts are equal.at n=14A106355
- Expansion of (x+1)*(x^3-x^2-x-1)/((1-x)*(x^2+2*x-1)*(x^2+x+1)).at n=10A108985
- Slowest growing sequence of semiprimes having the semiprime-pairwise-average property: for any i,j, (a(i)+a(j))/2 is semiprime.at n=5A114845
- Largest number <= sqrt(A179204(n)).at n=7A241097
- Expansion of chi(x^2) / phi(x) in powers of x where phi(), chi() are Ramanujan theta functions.at n=20A246712
- a(n) = A153880(A265905(n)); also the first differences of A265905.at n=5A265906
- The crystallogen sequence (a(n) = A018227(n)-4).at n=39A271996
- Square array A(1,k) = A265905(k), A(n>1,k) = A(n-1, k+1) - A(n-1, k); successive differences of A265905 read by descending antidiagonals as A(1,1), A(1,2), A(2,1), A(1,3), A(2,2), A(3,1), ...at n=22A275950
- Transpose of array A275950.at n=26A275951
- Indices i where a run of nonzero values starts in A305671.at n=24A305672
- Number of nonequivalent sets whose translations and reflections cover {1..n}.at n=16A329128
- Semiprimes that are the sum of two successive semiprimes and also the sum of three successive semiprimes.at n=36A370162
- Centered heptagonal numbers which are semiprime.at n=22A381960