Stuck on Project Euler #3 in python

Question

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

Ok, so i am working on projec

Answer 1

Here is my Python code:

num=600851475143
i=2 # Smallest prime factor
for k in range(0,num):
    if i >= num: # Prime factor of the number should not be greater than the number
        break
    elif num % i == 0: # Check if the number is evenly divisible by i
        num = num / i
    else:
        i= i + 1
print ("biggest prime number is: "+str(num))