Yes, it is one.
One is the only number that is a factor of every other number.
No prime number only has one factor. Each prime number has itself and 1 as factors. Now, the number 1 of course has only one factor, but it is technically not a prime number.
1 has one factor.
The only number with one factor is 1.
The only number with just one factor is 1.
prime number
The only number with one factor is 1.
One.
One is a factor of every number. One is only a multiple of itself.
It is: 1 which is neither a prime number or a composite number
1 has only one factor - itself.
The only common factor of 27 and 64 is one.