Project Euler Problem 3: Largest Prime Factor

The source code for this problem can be found here.

Problem Statement

The prime factors of \(13195\) are \(5,7,13\) and \(29\).

What is the largest prime factor of the number \(600851475143\)?

Solution Discussion

Factor the number \(600851475143\) and then find the largest prime factor.

Solution Implementation

from lib.numbertheory import factor

def solve():
    """ Compute the answer to Project Euler's problem #3 """
    target = 600851475143
    factors = factor(target)
    answer = max(factors.keys())  # factors = {prime: power}
    return answer

expected_answer = 6857

Compute the answer to Project Euler’s problem #3