What is the smallest prime number

The smallest prime number is 2, which is also the only even prime number. By definition, a prime number is a natural number greater than 1 that has exactly two distinct positive divisors: 1 and itself. The number 2 satisfies this perfectly—it's only divisible by 1 and 2, making it prime. What makes 2 particularly special is that it's the only even prime: all other even numbers are divisible by 2, automatically giving them at least three divisors (1, 2, and themselves), which disqualifies them from being prime.

Understanding that 2 is the smallest prime helps establish the foundation of number theory. The number 1 is not considered prime under modern mathematical definitions because including it would break the Fundamental Theorem of Arithmetic, which states that every integer greater than 1 has a unique prime factorization. If 1 were prime, factorizations wouldn't be unique (6 could be 2×3 or 1×2×3 or 1×1×2×3, etc.). After 2, the sequence of primes continues with odd numbers only: 3, 5, 7, 11, 13, and so on. The unique status of 2 as the smallest and only even prime makes it a special case in many mathematical theorems and proofs, which often treat 2 separately before addressing odd primes.