Fermat's Little Theorem
Concept
A primality test, a beautiful geometric proof of which is featured in Ellenberg's book.
Mentioned in 2 videos
Videos Mentioning Fermat's Little Theorem

Jordan Ellenberg: Mathematics of High-Dimensional Shapes and Geometries | Lex Fridman Podcast #190
Lex Fridman
A primality test, a beautiful geometric proof of which is featured in Ellenberg's book.

Richard Karp: Algorithms and Computational Complexity | Lex Fridman Podcast #111
Lex Fridman
A theorem in number theory used as an example for randomized algorithms to test whether a number is prime by raising a base to a power modulo a number.