13806
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
- 1
Divisibility
- Divisor Count
- 24
- Divisor Sum
- 32760
- Proper Divisor Sum (Aliquot Sum)
- 18954
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 4176
- Möbius Function
- 0
- Radical
- 4602
- 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
- yes
Recreational
- Happy Number
- no
- Harshad Number
- yes
- Narcissistic Number
- no
- Collatz Steps
- 58
- 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
- E.g.f.: 1/(1-x*exp(x)).at n=6A006153
- (d(n)-r(n))/2, where d = A008778 and r is the periodic sequence with fundamental period (1,1,0,1).at n=51A026052
- Hexagonal matchstick numbers: a(n) = 3*n*(3*n+1).at n=39A045945
- Number of cycles in range [A014137(n-1)..A014138(n-1)] of permutation A071661.at n=13A079437
- Sum of numbers in n-th upward diagonal of triangle in A079826.at n=44A079825
- Numbers k such that k + sum_of_digits(k) is a cube.at n=22A084661
- Number of 4k+3 primes whose Legendre-vector is not Dyck-path (A095103) in range ]2^n,2^(n+1)].at n=18A095093
- a(n) is the number of distinct n-th powers of functions {1, 2, 3, 4, 5, 6} -> {1, 2, 3, 4, 5, 6}.at n=29A103950
- a(n) is the number of distinct n-th powers of functions {1, 2, 3, 4, 5, 6} -> {1, 2, 3, 4, 5, 6}.at n=23A103950
- a(n) is the number of distinct n-th powers of functions {1, 2, 3, 4, 5, 6} -> {1, 2, 3, 4, 5, 6}.at n=19A103950
- a(n) is the number of distinct n-th powers of functions {1, 2, 3, 4, 5, 6} -> {1, 2, 3, 4, 5, 6}.at n=17A103950
- a(n) is the number of distinct n-th powers of functions {1, 2, 3, 4, 5, 6} -> {1, 2, 3, 4, 5, 6}.at n=13A103950
- a(n) is the number of distinct n-th powers of functions {1, 2, 3, 4, 5, 6} -> {1, 2, 3, 4, 5, 6}.at n=7A103950
- a(n) is the number of distinct n-th powers of functions {1, 2, 3, 4, 5, 6} -> {1, 2, 3, 4, 5, 6}.at n=31A103950
- a(n) is the number of distinct n-th powers of functions {1, 2, 3, 4, 5, 6} -> {1, 2, 3, 4, 5, 6}.at n=37A103950
- a(n) is the number of distinct n-th powers of functions {1, 2, 3, 4, 5, 6} -> {1, 2, 3, 4, 5, 6}.at n=11A103950
- G.f. satisfies: A(x) = 1 + x*A(x)*A(-x) + x^2*A(x)^2*A(-x)^2.at n=16A143926
- G.f. A(x) satisfies A(x) = (1 + x*A(x) + x^2*A(x)^2)^2.at n=7A143927
- a(n) = (4*n+1)*(4*n+2) = (4*n+2)!/(4*n)!.at n=29A157870
- a(n) = 25*n^2 + 25*n + 6.at n=23A177059