One has no proper factors.
No. Some proper factors are prime.
One has no proper factors.
1 doesn't have proper factors.
Prime numbers don't have proper factors.
The proper factors of 35 are 5 and 7.
Prime numbers don't have proper factors.
Zero doesn't have any proper factors.
One doesn't have any proper factors.
Prime numbers don't have proper factors.
The proper factors of 22 are 2 and 11.
Prime numbers don't have proper factors.