The original title is &quot;Computing 52 Factorial by Hand&quot; or &quot;Computing 52! by Hand&quot;. HN probably ate the &quot;!&quot;.<p>Edit: For the lazy: <a href="http:&#x2F;&#x2F;www.wolframalpha.com&#x2F;input&#x2F;?i=52%21" rel="nofollow">http:&#x2F;&#x2F;www.wolframalpha.com&#x2F;input&#x2F;?i=52%21</a> says that it&#x27;s 8x10^67, so the approximation here is only a 20% bigger and has the correct magnitude order.