A prime number has how many factors?

A prime number has exactly two factors: one and itself. This definition is fundamental to understanding prime numbers. For example, the number 5 is a prime number because its only divisors are 1 and 5. The uniqueness of prime numbers lies in their ability to be divided only by one and themselves without leaving a remainder, distinguishing them from composite numbers, which have additional factors.

In contrast, other choices do not accurately describe the nature of prime numbers. A prime number cannot have just one factor, nor can it possess three or many factors, as that would indicate it is not prime but rather a composite number. This clarity in definition is essential for identifying prime numbers in mathematics.