I will be watching it on iPlayer tonight
I was watching a Big Bang Theory bonanza last night, cant get enough of that!
"The best number is 73.... 73 is the twenty-first prime number. Its mirror, 37, is the twelfth and its mirror, 21, is the product of multiplying (hang on to your hats) 7 and 3.... In binary, 73 is a palindrome: 1-0-0-1-0-0-1, which backwards is 1-0-0-1-0-0-1."
Bazinga.