A prime number is a positive integer greater than 1 that has no positive integer divisors other than 1 and itself. In other words, it is a number that can only be divided evenly by 1 and itself. For example, the first few prime numbers are 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, and so on. Prime numbers are important in mathematics and computer science, and they have many practical applications in cryptography, coding theory, and other fields. The study of prime numbers is called number theory.