Project Euler Problem #3 - Largest Prime Factor (in Java)

Either use my PrimeFactorization class that I wrote here (the largest factor in the prime factorization result), or use just the necessary component of it (below) to find the largest prime factor.

import java.math.BigInteger;

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

public class Problem_3_Largest_Prime_Factor {

  public static void main(String[] args) {
    System.out.println(findLargestPrimeFactor(600851475143L));
    System.out.println(findLargestBigPrimeFactor(new BigInteger("600851475143")));
  }

  /**
    * Returns the largest prime factor of n.
    */
  public static long findLargestPrimeFactor(long n) {
    long primeFactor = 1L;
    long i = 2L;

    while (i <= n / i) {
      if (n % i == 0) {
        primeFactor = i;
        n /= i;
      } else {
        i++;
      }
    }

    if (primeFactor < n) primeFactor = n;

    return primeFactor;
  }

  /**
    * Returns the largest prime factor of n.
    */
  public static BigInteger findLargestBigPrimeFactor(BigInteger n) {
    BigInteger primeFactor = BigInteger.ONE;
    BigInteger i = new BigInteger("2");
  
    while (i.compareTo(n.divide(i)) <= 0) {
      if (n.mod(i).longValue() == 0) {
        primeFactor = i;
        n = n.divide(i);
      } else {
        i = i.add(BigInteger.ONE);
      }
    }

    if (primeFactor.compareTo(n) < 0) primeFactor = n;

    return primeFactor;
  }
}

         Created: May 11, 2014
    Last Updated: May 10, 2020
Completed in full by: Michael Yaworski