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.”
Jim Parsons was born in the year 1973. “The Alien Parasite Hypothesis” is the 73rd episode of The Big Bang Theory.