Euler_3

#-------------------------------------------------------------------------------
# Name:        module1
# Purpose:
#
# Author:      Stewart
#
# Created:     24/07/2012
# Copyright:   (c) Stewart 2012
# Licence:     <your licence>
#-------------------------------------------------------------------------------
#!/usr/bin/env python

#The prime factors of 13195 are 5, 7, 13 and 29.

#What is the largest prime factor of the number 600851475143 ?
import math

def is_prime(x):
    if x%2 ==0 or x%3 == 0 or x%5==0 or x%7==0:
        return False

    var = 2
    limit = x/2
    while var < limit:
        if x%var == 0:
            return False
        var = var + 1
    return True

fact = 1
while fact < math.sqrt(600851475143):
        if 600851475143%fact == 0:
         if is_prime(fact):
            print fact
        fact = fact + 1