# Why is 1 excluded as a prime number since it is divisible by 1 and itself?

A prime number has exactly two factors, which are 1 and itself. The number 1 has only one factor, since 1 and itself are the same number. Therefore, it does not meet the definition of a prime number. It is known as unity. It is neither a composite number nor a prime number.

### Is 173 a prime number?

Yes, 173 is a prime number. 173 is only divisible by 1 and itself, 173, making it a prime number. "a positive integer that is not divisible without remainder by any integer except itself and 1, with 1 often excluded: The integers 2, 3, 5, and 7 are prime numbers." - Dictionary.com definition for "prime number".

### Explain why 23 is considered to be a prime number?

A prime number is an integer, greater than 1, which is only divisible by 1 and by itself. A prime number is an integer, greater than 1, which is only divisible by 1 and by itself. A prime number is an integer, greater than 1, which is only divisible by 1 and by itself. A prime number is an integer, greater than 1, which is only divisible by 1 and by itself.

### What are the factors of 1 2 3 5 7 9 11?

The only factor of 1 is 1. 2 is a prime number. It is only evenly divisible by itself and one. 3 is a prime number. It is only evenly divisible by itself and one. 5 is a prime number. It is only evenly divisible by itself and one. 7 is a prime number. It is only evenly divisible by itself and one. The factors of 9 are: 1, 3, and 9. The only prime…

### Is 75 a prime number?

No 75 is not a prime number because it is divisible by numbers other than the number 1 and itself. No 75 is not a prime number because it is divisible by numbers other than the number 1 and itself. No 75 is not a prime number because it is divisible by numbers other than the number 1 and itself. No 75 is not a prime number because it is divisible by numbers other than…