How to store and perform operations on a large number of type int?

Question

C++ / C#

There is a type variable decimal; it has its own limit and at some point, when subtracting a smaller number, it goes into a negative value. Is there any other way to store a very large integer and perform mathematical operations on it. I'm new to Unity and C#, if it's not difficult, tell me more. If you need sources, write, I will share.
Number example:
91948102834320102834715231012347
This is the maximum value.

Answer 1

the easiest option is to use BigInteger

using System;
using System.Numerics;
          
public class Program
{
  public static void Main()
  {
    BigInteger hugeInt = BigInteger.Parse("91948102834320102834715231012347");
    Console.WriteLine(hugeInt);
  }
}

But in general, there is a feeling that you will suffer more with extra data types.
And if it's not a secret, what do you store in such numbers? Are you doing some kind of arithmetic with them?

Answer 2

Alternatively, you can implement algorithms for working with long numbers yourself. A branch of computer science is called long arithmetic. brestprog.by/topics/longarithmetics