In number theory, a Proth number is a number of the form
- N = k × 2n + 1
where k is an odd positive integer and n is a positive integer such that 2n > k.
Without the condition that 2n > k, all odd integers greater than 1 would be Proth numbers, but most pages lists them, too.
A Proth prime is a Proth number, which is prime.