title: Convert a number to shorter Alpha Numeric. Better than Base36?
body: <p>I'm generating a reference number which is a number to be entered by a user. It can be around 30 digits.</p>
  
  <p>I'm looking for a way to shorten the value to be entered by the user but I need to be able to convert it back to its original number.</p>
  
  <p>Currently base36 turns</p>
  
  <pre><code>999999999999999999999999999999 (30 digits)
  2OY99WNKL1A848GWKS0G (20 characters)
  </code></pre>
  
  <p>Id' probably hyphen this out to <code>2OY99-WNKL1-A848G-WKS0G</code> </p>