What is the prime factorization of 81?

The prime factorization of a number is the list of prime numbers that multiply together to give that number.

The prime factorization of 81 is 3 x 3 x 3 x 3, or 3^4. This shows that 81 can be written as the product of four factors of 3.

In other words, 81 is a perfect square, as it can be expressed as the square of the prime number 3.