The bit
In The Big Bang Theory season 4, episode 10, "The Alien Parasite Hypothesis," Sheldon announces that the best number is 73 — and, being Sheldon, backs it up with a rapid-fire list of reasons. Here they are, checked by a robot.
The proof (verified)
- 73 is the 21st prime number. (2, 3, 5, 7, 11, … 71, 73.)
- Its mirror, 37, is the 12th prime.
- And 12 mirrored is 21 — right back where we started.
- 21 = 7 × 3, the two digits of 73 itself.
- In binary, 73 is
1001001, a palindrome: same forwards and backwards.
Most numbers are lucky to have one party trick. 73 has a whole act.
Bonus: ham radio approves
On the air, "73" is classic CW/ham-radio shorthand for best regards — the polite way to sign off. So 73 is not only the best number, it's also a friendly goodbye. In Morse: --... ...--