13519
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
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 14760
- Proper Divisor Sum (Aliquot Sum)
- 1241
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 12280
- Möbius Function
- 1
- Radical
- 13519
- 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
- 63
- 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
- Number of shuffles in Guy's shuffle (see A035485) for the card that is at the top of the deck after n shuffles to come to the top again.at n=52A081058
- Number of consecutive prime runs of 6 primes congruent to 1 mod 4 below 10^n.at n=7A092651
- Total number of palindromic primes in base 5 with n digits.at n=14A117780
- a(n) = 1331*n - 1122.at n=10A157441
- a(n) = 338*n - 1.at n=39A157999
- a(n) = 676*n - 1.at n=19A158393
- a(n) = 20*n^2 - 1.at n=25A158491
- a(n) = 80*n^2 - 1.at n=12A158774
- Number of distinct solutions of sum{i=1..3}(x(2i-1)*x(2i)) = 0 (mod n), with x() only in 1..n-1.at n=14A180774
- a(n) = a(n-2) + a(n-1) + floor(n/2) + 1 for n > 1 and a(0)=0, a(1)=1.at n=18A215005
- a(n) is the number of primes occurring between A053182(n) and A053183(n) (excluding the endpoints).at n=13A238399
- Number of perfect matchings on a Möbius strip of width 4 and length n.at n=7A263201
- a(n) is obtained by applying the map k -> composite(k) n times, starting at n.at n=30A280327
- Numbers k such that (184*10^k - 1)/3 is prime.at n=21A282340
- Numbers k such that (56*10^k + 691)/9 is prime.at n=21A291866
- Solution of the complementary equation a(n) = a(n-1) + a(n-2) + b(n), where a(0) = 1, a(1) = 2, b(0) = 3, b(1) = 4, b(2) = 5, and (a(n)) and (b(n)) are increasing complementary sequences.at n=16A295949
- Coefficients of the polynomials generated by the e.g.f. cosh(x*z)*(x-1)/(x-exp(z*(x-1))), triangle read by rows, T(n,k) for 0 <= k <= n.at n=41A318143