title: Modulus PHP Problem
body: <p>I have a problem, I am trying to calculate what the lowest prime is of a number but I do not understand the result that PHP is giving me. </p>
  
  <p>If I have this number</p>
  
  <pre><code> $number = 600851475143;
  </code></pre>
  
  <p>Then I modulus it:</p>
  
  <pre><code>$primes = array( 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97);
  
      foreach($primes as $key=&gt;$value) {    
          if($number % $value == 0 ) {echo $value; break; }
      }
  </code></pre>
  
  <p>Why is it that $value = 3? If $value = 3, that means that 600851475143 / 3 <strong>should</strong> be an integer, but its not. So I do not understand why that if() evaluates to true?</p>