13782
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
- 4
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 27576
- Proper Divisor Sum (Aliquot Sum)
- 13794
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- yes
Derived Values
- Euler's Totient
- 4592
- Möbius Function
- -1
- Radical
- 13782
- Omega Function (Ω)
- 3
- Little Omega Function (ω)
- 3
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
- 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
- Numbers k such that 2*3^k + 1 is prime.at n=28A003306
- Numbers k such that k, k+1, k+2 and k+3 have the same number of divisors.at n=16A006601
- Numbers k such that k through k+4 all have the same number of divisors.at n=2A049051
- Number of permutations satisfying -k<=p(i)-i<=r and p(i)-i not in I, i=1..n, with k=3, r=3, I={0,1,2}.at n=22A079988
- Difference between A007678(2n)/(2n) and (n-1)^2.at n=36A085611
- Number of numbers with 6 decimal digits and sum of digits = n.at n=15A090581
- Number of numbers with 6 decimal digits and sum of digits = n.at n=38A090581
- a(n) = 1 + (the n-th term in sequence A_n, ignoring the offset), or a(n) = -1 if A_n has fewer than n terms.at n=17A102288
- Triangle read by rows: T(n,k) is number of paths from (0,0) to (3n,0) that stay in the first quadrant (but may touch the horizontal axis), consisting of steps u=(2,1),U=(1,2), or d=(1,-1) and having height of last peak equal to k.at n=48A109158
- a(n) = 7 + floor((1 + Sum_{j=1..n-1} a(j))/4).at n=34A120165
- L.g.f.: Sum_{n>=1} a(n)*x^n/n = Sum_{n>=1} (1 + C(2n-1,n-1)*x)^n * x^n/n.at n=5A159321
- Numbers such that n^2 = 29 mod 1193.at n=23A165989
- Number of partitions where the number of 1's and 2's are equal.at n=47A174455
- Total area of the shadows of the three views of the shell model of partitions, version "Tree", with n shells.at n=19A210980
- G.f. satisfies A(x) = (1 + x^2)*(1 + x*A(x)^2).at n=9A215576
- Number of Hamiltonian cycles on 2n X 2n grid with at least the symmetries of two reflections and 180-degree rotation.at n=5A238818
- Number of length 3+2 0..n arrays with every three consecutive terms having the sum of some two elements equal to twice the third.at n=44A248436
- a(0) = 1; thereafter a(n) = 5*n^2 - 5*n + 2.at n=53A386485