Project Euler Question 3

A prime factor is a natural number whose only factors are 1 and itself. The first few prime factors are 2, 3, 5, and 7. In this question, we are supposed to find the largest prime factor of the integer 600851475143.

def largest_prime_factor(n):
    prime_candidates=list(range(2,n))
    for candidate in prime_candidates:    
        for num in prime_candidates:
            # checking whether each integer is prime or not
            if num != candidate and num%candidate==0:
                # removing the composite numbers from the list of candidates
                prime_candidates.remove(num)
    return prime_candidates

def get_factors(m):
    prime_factors=list(largest_prime_factor(m))
    prime_factors_set=set(prime_factors)
    for prime in prime_factors:
        if 600851475143%prime != 0:
            prime_factors_set.remove(prime)
    return prime_factors_set

m=int(600851475143**0.5+1)
output=(max(get_factors(m)))
print(output)