C# Program - Find the largest prime factor of a number

  number = num

  Step 1: If num is divisible by 2, store
  largest prime factor as 2. keep on dividing
  num until it is not divisible by 2. After
  each division, update num as num/2.

  Step 2: At this point, num must be odd.
  Starting with 3 to square root of num, if
  divisible, divide and update num, and update
  largest prime factor.

  Step 3: if the modified num is greater than
  2, update the largest prime factor with num.

using System;
 
class MyProgram {
  static long MaxPrime(long num) {
    long CurrMaxPrime = -1;

    //If num is divisible by 2, store CurrMaxPrime
    //as 2. keep on dividing num until it is not 
    //divisible by 2. After each division, update 
    //num as num/2.
    if(num % 2 == 0) {
      CurrMaxPrime = 2;
      while(num % 2 == 0){
        num = num/2;
      }
    }
    
    //At this point, num must be odd. Starting with 
    //3 to square root of num , if divisible, divide 
    //and update num, and update CurrMaxPrime
    for(long i = 3; i <= Math.Sqrt(num); i += 2) {
      while(num % i == 0) {
        CurrMaxPrime = i;
        num = num/i;
      }
    }

    //if the modified num is greater than 2, 
    //update the CurrMaxPrime with num 
    if (num > 2) 
      CurrMaxPrime = num;

    return CurrMaxPrime;
  }

  static void Main(string[] args) {
    long x, y, z;
    x = 42;
    y = 1092;
    z = 695467363456;

    Console.WriteLine("Largest prime factor of "+ x
                       + " is: "+ MaxPrime(x));
    Console.WriteLine("Largest prime factor of "+ y
                       + " is: "+ MaxPrime(y));
    Console.WriteLine("Largest prime factor of "+ z
                       + " is: "+ MaxPrime(z));
  }
}