13518
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
- 2
Divisibility
- Divisor Count
- 12
- Divisor Sum
- 29328
- Proper Divisor Sum (Aliquot Sum)
- 15810
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 4500
- Möbius Function
- 0
- Radical
- 4506
- Omega Function (Ω)
- 4
- 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
- yes
- Narcissistic Number
- no
- Collatz Steps
- 63
- 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
- 30 'Reverse and Add' steps are needed to reach a palindrome.at n=3A065319
- Interprimes which are of the form s*prime, s=18.at n=26A075293
- G.f.: A(x) = x/(1 - x - G001190(x^2)), where G001190 is the g.f. of A001190, the Wedderburn-Etherington numbers (binary rooted trees).at n=17A093126
- Expansion of solution to an algebraic functional equation.at n=8A113299
- Multiples of 18 containing a 18 in their decimal representation.at n=34A121038
- a(1)=1, then a(n) = smallest number whose square is larger than 2*(a(n-1))^2.at n=25A175539
- Number of -n..n arrays x(0..3) of 4 elements with zero sum and elements alternately strictly increasing and strictly decreasing.at n=17A200058
- G.f.: Product_{n>=0} (1+a(n)*x^(n+1))^3 = Sum_{n>=0} a(n)*x^n.at n=6A203508
- Number of binary arrays indicating the locations of trailing edge maxima of a random length-n 0..2 array extended with zeros and convolved with -1,2,-1.at n=17A222037
- Positions of record high water marks in A246024.at n=34A246026
- Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 238", based on the 5-celled von Neumann neighborhood.at n=33A270986
- Sum of the third largest parts of the partitions of n into 5 parts.at n=46A308825
- Number of subsets of {1..n} whose greatest element can be written as a (strictly) positive linear combination of the others.at n=32A365043
- Consecutive states of the linear congruential pseudo-random number generator for Smalltalk-80 when started at 1.at n=25A384220
- Consecutive states of the linear congruential pseudo-random number generator 171*s mod 30269 when started at s=1.at n=33A385031