# Python Program for Find largest prime factor of a number

• Difficulty Level : Hard
• Last Updated : 17 Feb, 2018

Given a positive integer \’n\'( 1 <= n <= 1015). Find the largest prime factor of a number.

Input: 6
Output: 3
Explanation
Prime factor of 6 are- 2, 3
Largest of them is \'3\'

Input: 15
Output: 5


## Python3

 # Python3 code to find largest prime# factor of numberimport math  # A function to find largest prime factordef maxPrimeFactors (n):          # Initialize the maximum prime factor    # variable with the lowest one    maxPrime = -1          # Print the number of 2s that divide n    while n % 2 == 0:        maxPrime = 2        n >>= 1     # equivalent to n /= 2              # n must be odd at this point,     # thus skip the even numbers and     # iterate only for odd integers    for i in range(3, int(math.sqrt(n)) + 1, 2):        while n % i == 0:            maxPrime = i            n = n / i          # This condition is to handle the     # case when n is a prime number     # greater than 2    if n > 2:        maxPrime = n          return int(maxPrime)  # Driver code to test above functionn = 15print(maxPrimeFactors(n))  n = 25698751364526print(maxPrimeFactors(n))  # This code is contributed by "Sharad_Bhardwaj".

Output:

5
328513


Time complexity: Auxiliary space: Please refer complete article on Find largest prime factor of a number for more details!

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