I need an optimal algorithm to find the largest divisor of a number N. Preferably in C++ or C#

Question

I am currently using the following code but its very slow for large numbers

        static int divisor(int number)
        {
            int i;
                    


        

Answer 1

• Find the first prime which divides the number N.
• Let's say that prime is d.
• Divide N by d.
• This is the required result that you want.