13965
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 24
- Digital Root
- 6
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 24
- Divisor Sum
- 27360
- Proper Divisor Sum (Aliquot Sum)
- 13395
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 6048
- Möbius Function
- 0
- Radical
- 1995
- Omega Function (Ω)
- 5
- Little Omega Function (ω)
- 4
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
- 151
- 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
- Expansion of g.f. 1/((1-x)*(1-2*x)*(1-6*x)).at n=5A016200
- a(n) = n*(31*n + 1)/2.at n=30A022289
- Number of partitions of n into parts not of the form 23k, 23k+9 or 23k-9. Also number of partitions with at most 8 parts of size 1 and differences between parts at distance 10 are greater than 1.at n=35A035997
- The number phi_3(n) of Frobenius partitions that allow up to 3 repetitions of an integer in a row.at n=23A053992
- Triangle T(n,m) of numbers of m-block T_0-covers of a labeled n-set, m = 0..2^n - 1.at n=35A059202
- Numbers k such that the harmonic mean of the divisors of k is the square of a rational number.at n=9A074266
- Fifth column (m=4) of (1,6)-Pascal triangle A096956.at n=18A096958
- a(n) = n*(4*n^2 + 2*n + 1).at n=15A110451
- Coefficients of x^n in the (n+1)-th self-composition of the g.f. of A120009, so that: a(n) = [x^n] { (x-x^2) o x/(1-(n+1)*x) o (1-sqrt(1-4*x))/2 } for n>=1.at n=5A120015
- Numbers n for which nontrivial positive magic squares of exactly 10 different orders with magic sum n exist. For a definition of nontrivial positive magic squares, see A125005.at n=35A125017
- Coefficients of tribonacci numbers expansion : similar to the Fibonacci number expansion given in Steve Roman's Umbral Calculus.at n=32A137431
- Triangle T(n, k) = binomial(n, k) * Sum_{j=k..n} StirlingS1(n, j)*StirlingS1(j, k), read by rows.at n=25A142472
- Coefficients in the expansion of C^4/B^5, in Watson's notation of page 106.at n=9A160506
- a(n) = ((2^b-1)/phi(n))*Sum_{d|n} Moebius(n/d)*d^(b-1) for b = 4.at n=21A160892
- Ordered (2,2)-selections from the multiset {1,1,2,2,3,3,...,n,n}.at n=15A188667
- Odd numbers n such that 2n/sigma(n) - 1 = 1/x for some positive integer x.at n=17A222263
- Number of subsets of {1,2,...,n-12} without differences equal to 2, 4, 6, 8, 10 or 12.at n=49A224813
- Number of net regularizable trees with 4n+2 vertices.at n=8A292096
- a(n) = product of total number of 0's and total number of 1's in binary expansions of 0, ..., n.at n=49A301896
- Odd numbers k such that sigma(k^2) > 2*k^2 and A003415(sigma(k^2)) < k^2.at n=33A347891