What is the smallest prime number?

The smallest prime number is 2. A prime number is defined as a natural number greater than 1 that has no positive divisors other than 1 and itself. This means that a prime number can only be divided evenly by 1 and the number itself.

In the case of 2, it is divisible only by 1 and 2, meeting the criteria for a prime number. Furthermore, it is unique among prime numbers because it is the only even prime number; all other even numbers can be divided by 2, thus having at least three divisors: 1, 2, and the number itself. This makes them non-prime.

Numbers like 1, 3, and 5 are not valid, because 1 is not considered a prime number, and while 3 and 5 are prime, they are both greater than 2, which confirms that 2 is indeed the smallest prime number.