(n)
return result
Euler's totient function or Phi function.
    Time Complexity: O(sqrt(n)).
Euler's totient function or Phi function.
    Time Complexity: O(sqrt(n)).
Euler s totient function or Phi function . Time Complexity : O ( sqrt ( n )) .
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
            result -= result // i
    if n > 1:
        result -= result // n;
    return result;
def euler_totient ( n ) : result = n for i in range ( 2 , int ( n ** 0.5 ) + 1 ) : if n % i == 0 : while n % i == 0 : n //= i result -= result // i if n > 1 : result -= result // n return result