13529
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 20
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 13776
- Proper Divisor Sum (Aliquot Sum)
- 247
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 13284
- Möbius Function
- 1
- Radical
- 13529
- Omega Function (Ω)
- 2
- Little Omega Function (ω)
- 2
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
- 37
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- yes
- 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
- a(n) = a(n-1) + a(n-2) + 1, with a(0) = a(1) = 1.at n=19A001595
- Number of n-node bipartite graphs not determined by their spectra.at n=10A006612
- a(n) = (2*n+1) * (4*n-1).at n=41A033566
- Base-9 palindromes that start with 2.at n=25A043029
- a(n) = 2*Fibonacci(n+2) + ((-1)^n - 3)/2.at n=18A066629
- Duplicate of A066629.at n=18A078697
- Number of initial odd numbers in class n of the iterated phi function.at n=33A092878
- Numbers that are the sum of exactly two sets of Fibonacci numbers.at n=33A122194
- Row sums of triangle A131779.at n=18A131780
- Diagonal sums of number triangle A132046.at n=19A154327
- Number of n X 4 binary arrays with each 1 adjacent to exactly one 0 vertically and one 0 horizontally.at n=9A183346
- Number of disconnected 4-regular simple graphs on n vertices with girth at least 6.at n=63A185246
- Dispersion of ([n*x+n+x]), where x=(golden ratio) and [ ]=floor, by antidiagonals.at n=45A191435
- a(2) = 1, then (p-1)*(p-4)/2, with p = prime(n), n > 2.at n=37A200050
- Number of (n+1)X3 0..3 arrays containing all values 0..3 with every 2X2 subblock having one or two distinct values, and new values 0..3 introduced in row major order.at n=3A209963
- Number of (n+1)X5 0..3 arrays containing all values 0..3 with every 2X2 subblock having one or two distinct values, and new values 0..3 introduced in row major order.at n=1A209965
- T(n,k)=Number of (n+1)X(k+1) 0..3 arrays containing all values 0..3 with every 2X2 subblock having one or two distinct values, and new values 0..3 introduced in row major order.at n=11A209969
- T(n,k)=Number of (n+1)X(k+1) 0..3 arrays containing all values 0..3 with every 2X2 subblock having one or two distinct values, and new values 0..3 introduced in row major order.at n=13A209969
- Number of distinct regular languages over 4-ary alphabet, whose minimum regular expression has reverse Polish length n.at n=7A211945
- Least number k such that n divides gcd(sigma(k), phi(k)) (A009223).at n=40A222713