13692
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 21
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 24
- Divisor Sum
- 36736
- Proper Divisor Sum (Aliquot Sum)
- 23044
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 3888
- Möbius Function
- 0
- Radical
- 6846
- 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
- yes
- 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
- yes
- Odd
- no
Appears in sequences
- Number of partially achiral planted trees with n nodes.at n=19A003237
- Number of points on surface of cuboctahedron (or icosahedron): a(0) = 1; for n > 0, a(n) = 10n^2 + 2. Also coordination sequence for f.c.c. or A_3 or D_3 lattice.at n=37A005901
- Numbers k such that the continued fraction for sqrt(k) has even period and if the last term of the periodic part is deleted the central term is 78.at n=24A031576
- Numbers k such that the least term in the periodic part of the continued fraction for sqrt(k) is 78.at n=2A031756
- "EFK" (unordered, size, unlabeled) transform of 1,3,5,7,...at n=16A032304
- a(n) = n! * Sum_{k=0..n-2} 1/k!.at n=7A038154
- Number of nonempty subsets of {1,2,...,n} in which exactly 2/5 of the elements are <= n/2.at n=17A047166
- Number of nonempty subsets of {1,2,...,n} in which exactly 3/5 of the elements are <= n/2.at n=17A047167
- Multiply by 1, add 1, multiply by 2, add 2, etc., starting with 0.at n=13A082458
- Triangle read by rows: T(n,m) = number of T_0-multigraphs with n edges and m vertices(n>=2, 3<=m<=2*n).at n=16A093855
- Number of compositions of n into 4 parts such that no two adjacent parts are equal.at n=41A106353
- <h[d+1,d-1],s[d,d]*s[d,d]*s[d,d]> where h[d+1,d-1] is a homogeneous symmetric function, s[d,d] is a Schur function indexed by two parts, * represents the Kronecker product and <, > is the standard scalar product on symmetric functions.at n=32A115376
- Average of twin-prime pairs for pairs that are expressible as the sum of two triangular numbers.at n=26A117313
- a(n) = 2n+7^n-5^n.at n=5A121203
- Averages of twin prime pairs that are sums of 4 consecutive averages of twin prime pairs.at n=16A160918
- Triangle read by rows: T(n,k) is the number of 2-compositions of n having k columns with an even sum (0<=k<=floor(n/2)).at n=27A181327
- Expansion of (16+24*x+2*x^2)/(x-1)^6.at n=6A190049
- G.f. A(x) satisfies: x = Sum_{n>=1} 1/A(x)^(8*n) * Product_{k=1..n} (1 - 1/A(x)^(2*k-1)).at n=5A214694
- Averages q of twin prime pairs, such that q concatenated to q is also the average of a twin prime pair.at n=19A235109
- Numbers n such that n is the average of four consecutive primes n-5, n-1, n+1 and n+5.at n=26A258088