Because 1 is the factor of all numbers including all prime and coprime numbers. And final factor of a number is the number itself.
Now take an example like we have to find the factor of 10. Starting from 1 we now check 2, 3 ,4 and 5 so 5 is the next factor of 10 which is half of it and the final factor after the half of the number is the number itself 10.
So in total we have total 3 factors of 10, 1,5 and 10.
For more details on factors follow the link :
https://brainly.com/question/6810544
