1309
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 13
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 1728
- Proper Divisor Sum (Aliquot Sum)
- 419
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 960
- Möbius Function
- -1
- Radical
- 1309
- 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
- yes
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 145
- 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
- no
- Odd
- yes
Appears in sequences
- Boustrophedon transform of all-1's sequence.at n=7A000667
- If F(n) is the n-th Fibonacci number, then a(2n) = (F(2n+1) + F(n+2))/2 and a(2n+1) = (F(2n+2) + F(n+1))/2.at n=16A001224
- Expansion of 1/(1 - 11*x + x^2).at n=3A004190
- Numbers k such that k, k+1 and k+2 have the same number of divisors.at n=25A005238
- a(n) = n*(n+4)*(n+5)/6.at n=17A005586
- Triangulations of a square with no separating triangles (previously "Bordered triangulations of sphere with n nodes").at n=7A006674
- Number of non-Abelian metacyclic groups of order p^n (p odd).at n=41A007983
- Coordination sequence T1 for Zeolite Code ATO.at n=24A008265
- Expansion of e.g.f. log(1+tanh(x))/exp(x).at n=10A009393
- Expansion of Product_{k>=1} (1 - x^k)^17.at n=5A010823
- a(n) = floor( n*(n-1)*(n-2)/25 ).at n=33A011907
- a(n) = floor(n*(n-1)*(n-2)/30).at n=35A011912
- Orders of cyclotomic polynomials containing a coefficient the absolute value of which is >= 3.at n=8A013591
- Convolution of Catalan numbers and powers of 2.at n=7A014318
- Numbers k such that phi(k + 5) | sigma(k).at n=52A015821
- Expansion of 1/(1 - x^13 - x^14 - ...).at n=67A017907
- Cycle class sequence c(n) (the number of true cycles of length n in which a certain node is included) for zeolite MFI = ZSM-5 Nan[AlnSi96-nO192] starting with a T11 atom.at n=10A019166
- Pseudoprimes to base 67.at n=20A020195
- Pseudoprimes to base 89.at n=24A020217
- Numbers k such that the continued fraction for sqrt(k) has period 30.at n=10A020369