Answer: 23
Explanation: When finding the prime factorization of a number, we normally would set up a factor tree with two branches. Then, we would choose factors other than 1 and the number itself for the first branches of the tree. In this problem however, notice that 23 is a prime number so the only factors of 23 are 1 and 23. This means that we can go straight to our answer without using a factor tree. However, it's important to understand that the answer to this problem is not 1 × 23 it would just be 23. Therefore, the prime factorization of 23 would be 23.