The factor * * * of 27 is: 1, 3,9,27 * * *:

Where 1 is neither prime nor composite, and 9 and 27 are both composite.

Only 3 is a prime number,

So the prime factor of 27 is only 3.

Extended data:

A prime factor (prime factor or prime factor) in number theory refers to a prime number that can be divisible by a given positive integer.

Every composite number can be written as the multiplication of several prime numbers (also called prime numbers), which are called prime factors of this composite number.

For example, 27 in the question can be decomposed into 3*3*3.

References:

Prime factor-Baidu Encyclopedia