13546
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 19
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 21924
- Proper Divisor Sum (Aliquot Sum)
- 8378
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 6240
- Möbius Function
- -1
- Radical
- 13546
- 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
- 37
- 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
- a(n) = floor(n*phi^13), where phi is the golden ratio, A001622.at n=26A004928
- a(n) = round(n*phi^13), where phi is the golden ratio, A001622.at n=26A004948
- Numbers k for which 10k+1, 10k+3, 10k+7 and 10k+9 are primes.at n=42A007811
- Triangle of q-binomial coefficients for q=-5.at n=17A015113
- Triangle of q-binomial coefficients for q=-5.at n=18A015113
- Gaussian binomial coefficient [ n,2 ] for q = -5.at n=3A015255
- Gaussian binomial coefficient [ n,3 ] for q = -5.at n=2A015272
- Numbers n such that Fibonacci(n) is not squarefree, but for all proper divisors k of n, Fibonacci(k) is squarefree.at n=31A065069
- Centered 15-gonal numbers: a(n) = (15*n^2 - 15*n + 2)/2.at n=42A069128
- a(n) = (n^3)/2 + (3*n^2)/2 + 3*n + 3.at n=28A127873
- a(n) = 7*n^2 + 14*n + 1.at n=43A131878
- Triangle read by rows, iterates of matrix X * [1,0,0,0,...], where X = an infinite lower bidiagonal matrix with [1,3,1,3,1,3,...] in the main diagonal and [1,1,1,...] in the subdiagonal.at n=59A140070
- Second elementary symmetric function of the first n terms of (1,1,2,2,3,3,4,4,...).at n=23A203246
- Number of (w,x,y,z) with all terms in {1,...,n} and w+x<y+z.at n=13A212523
- Sequence of coefficients of x in marked mesh pattern generating function Q_{n,132}^(4,0,-,0)(x).at n=6A213164
- Number of sets of exactly seven positive integers <= n having a square element sum.at n=16A281867
- Numbers k such that k!6 - 27 is prime, where k!6 is the sextuple factorial number (A085158).at n=24A289698
- Number of permutations of [n] whose lengths of increasing runs are distinct Fibonacci numbers.at n=10A317444
- a(n) = Sum_{k=0..n} phi(k^2 + 1), where phi is the Euler totient function (A000010).at n=39A333170
- a(1) = 2; for n > 1, a(n) = a(n-1)*prime(n) if a(n-1)<=prime(n), otherwise a(n) = a(n-1)-prime(n).at n=36A382619