"""
The prime factors of 13195 are 5, 7, 13 and 29.
What is the largest prime factor of the number 600851475143?
"""

def solution():
    divisor = 2
    num = 600851475143
    while True:
        if (num == divisor):
            return num
        elif (num % divisor == 0):
            num /= divisor
        else:
            divisor += 1
                
            
