Definition:Sheldon Prime

Definition

A Sheldon prime is a prime number which satisfies both the product property and the mirror property.

Also see

• Sheldon Conjecture: There is only $1$ Sheldon prime, and that is $73$.

Historical Note

The name Sheldon prime was named for the fictional physicist Sheldon Cooper, who expounded upon the properties of the number $73$ in (fittingly) episode $73$ of The Big Bang Theory, by Lee Aronsohn, Jim Reynolds and Maria Ferrari:

Sheldon Cooper:

$73$ is the best number:

$73$ is the $21$st prime number.

Its mirror $37$ is the $12$th prime number.

Its mirror $21$ is the product of multiplying, hang on to your hats, $7$ by $3$.

Eh? Eh? Did I lie?

Leonard Hofstadter:

We get it. $73$ is the Chuck Norris of numbers.

Sheldon Cooper:

Chuck Norris wishes.

In binary, $73$ is a palindrome: $1,001,001$, which backwards is $1,001,001$, exactly the same.

All Chuck Norris backwards gets you is Sirron Kcuhc!

Sources

• Nov. 2015: Jessie Byrnes, Chris Spicer and Alyssa Turnquist: The Sheldon Conjecture (Math Horizons Vol. 23: pp. 12 – 15)  www.jstor.org/stable/10.4169/mathhorizons.23.2.12

• Jan. 2019: Carl Pomerance and Chris Spicer: Proof of the Sheldon Conjecture (Amer. Math. Monthly Vol. 121, no. 1: pp. 1 – 10)