13239
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
- 6
- Divisor Sum
- 19136
- Proper Divisor Sum (Aliquot Sum)
- 5897
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 8820
- Möbius Function
- 0
- Radical
- 4413
- 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
- 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
- Number of graphs on n nodes with 3 cliques.at n=19A005289
- a(n) = Sum_{k=0..n+2} (k+1) * A026323(n, k).at n=7A027312
- Numbers k such that sigma(k-3) + sigma(k+3) = sigma(2*k).at n=17A067129
- Integers k such that 10^k + 33 is prime.at n=21A107084
- a(n) = (2^(semiprime(n)-1)) modulo (semiprime(n)^2).at n=38A115948
- Numbers k for which digitsum(k) + digitsum(k^2) + digitsum(k^3) = digitsum(k^4).at n=31A118470
- Partial sums of PartitionsP of Fibonacci numbers.at n=9A152477
- Number of distinct solutions of sum{i=1..3}(x(2i-1)*x(2i)) = 1 (mod n), with x() only in 1..n-1.at n=14A180785
- Composite Flavius' numbers (A000960) whose prime factors are again Flavius' numbers.at n=11A181489
- Number of partitions p of n such that max(p)-min(p) = 6.at n=45A218569
- Numbers such that Liouville's function (A002819) and the little omega analog to Liouville's function (A174863) are equal.at n=44A224987
- The Pnictogen sequence: a(n) = A018227(n)-3.at n=39A271995
- G.f. A(x) satisfies: A(x) = (1/(1 - x)) * A(x^3)*A(x^5)*A(x^7)* ... *A(x^(2*k-1))* ...at n=53A308283