#5. Euler's totient function, also known as phi-function ϕ(n), counts the number of integers between 1 and n inclusive, which are coprime to n. (Two numbers are coprime if their greatest common divisor (GCD) equals 1). """ def euler_totient(n): """Euler's totient function or Phi function. Time Complexity: O(sqrt(n)).""" result = n for i in range(2, int(n ** 0.5) + 1): if n % i == 0: while n % i == 0: n //= i.

#5. Euler's totient function, also known as phi-function ϕ(n), counts the number of integers between 1 and n inclusive, which are coprime to n. (Two numbers are coprime if their greatest common divisor (GCD) equals 1). """ def euler_totient(n): """Euler's totient function or Phi function. Time Complexity: O(sqrt(n)).""" result = n for i in range(2, int(n ** 0.5) + 1): if n % i == 0: while n % i == 0: n //= i.