A prime number is a positive integer greater than 1 that has no positive divisors other than 1 and itself. For instance, is 7 a prime number? The answer is yes, since 7 only has two positive divisors: 1 and 7.
Determining whether a number is prime has practical applications, including cryptography, computer science, and mathematics. One of the first significant historical developments in prime number theory was Euclid’s proof that there are infinitely many prime numbers.