Natter 73: is the Chuck Norris of numbers.
or maybe
Natter 73: is the Chuck Norris of natters.
This is likely because I have been watching a LOT of Big Bang as I try and clear my recorded tv...
So I had to look up the whole exchange because all I could remember was that Chuck Norris was involved with 73 and Sheldon's shirt. Gotta love Google.
Sheldon: "The best number is 73. Why? 73 is the 21st prime number. Its mirror, 37, is the 12th and its mirror, 21, is the product of multiplying 7 and 3... and in binary 73 is a palindrome, 1001001, which backwards is 1001001."
Leonard: "73 is the Chuck Norris of numbers!"
Sheldon: "Chuck Norris wishes... all Chuck Norris backwards gets you is Sirron Kcuhc!"
And now I am thinking it would be better to toss that suggestion in without context, because that would be the right thing to do.