title: Numbers that are emirps
body: <p>So i need to print out the first 100 emirps number. I got the prime and reverse it. But for some reason it still print out a few number wrong, i.e. it prints out 101, which is not an emirps. Is it something wrong with my method to determine if the prime is an emirp? </p>
  
  <pre><code>//Method to know if the prime is a emirp
  public static boolean isEmirp(int x){
      return isPrime(x) &amp;&amp; isPrime(reverse(x));
  
  }
  //Method that reverses the prime
  public static int reverse(int r){
      if(r&lt;10) return r;
      return switchnum(r%10,r/10);
  
  }
  //Method that creates the emirp/reverse prime
  public static int switchnum(int a, int b){
      if(b&lt;1) return a;
      return switchnum(a*10+b%10,b/10);
  }
  </code></pre>