title: How to reverse an integer in haskell?
body: <p>I need help on how to reverse a <code>Integer</code> in Haskell with the following type signature:</p>
  
  <pre><code>reverseInt :: Integer -&gt; Integer
  reverseInt a = undefined -- help here
  </code></pre>
  
  <p>I need the <code>Integer</code> input number to be reversed like the example below.</p>
  
  <p><strong>Example:</strong></p>
  
  <pre><code>&gt; reverseInt 1989
  9891
  </code></pre>