title: How far can I go with this program of computing prime numbers?
body: <pre><code>#include &lt;iostream&gt;
  
  using namespace std;
  
  int ifprime(long long int);
  int main()
  
  {
      long long int number;   
      cout&lt;&lt;"Enter the number of prime numbers you want to know:\n";
      cin&gt;&gt;number;    //number is the number of prime numbers to be displayed
      long long int j=0;
      long long int m=2;      //m would be used as consecutive natural numbers on which, test of prime number is performed
  
      while (1&lt;2)
      {
          if(ifprime(m)==1)
          {
              j+=1;   // j is the counter of the prime numbers found and displayed
              cout&lt;&lt;m&lt;&lt;endl;
          }
          m+=1;
          if(j==number)
          {
              break;
          }
      }
  
  }
  
  int ifprime(long long int a)
  {
      for(int i=2;i&lt;a;i++)
      {
          if(a%i==0)
          {
              return 0;
          }
      }
      return 1;
  }
  </code></pre>
  
  <p>The range of <code>long long int</code> seems to be small compared to the biggest primes known :/</p>
  
  <p>Even if I were to compute the last prime number in the range of the <code>long long int</code> , can I compute the time it would take to compute that number?</p>