Vantieghem's Theorem

Vantieghem's theorem is a primality criterion stating that a natural number n of at least 3 is prime if and only if a particular product of terms built from powers of 2 satisfies a specific congruence modulo n. The criterion gives a necessary and sufficient condition for primality, and it also has a polynomial formulation, extending its use beyond simple numerical testing into algebraic settings. This description is adapted from Wikipedia contributors under CC BY-SA 4.0; changes were made. https://creativecommons.org/licenses/by-sa/4.0/