title: BigInteger to Hexadecimal
body: <p>Quick question...</p>
  
  <p>I have a stupidly long <code>BigInteger</code> which I would like to write to a file as a hex string.</p>
  
  <p>I know Java provides the <code>.toString(16)</code> method which does this, but I can't find an equivalent in C#.</p>
  
  <p>I'm using <code>System.Numerics.BigInteger</code> from .NET 4.0.</p>
  
  <p>Thanks</p>