Both, 911 and 23 are prime.
11, 23, 53, no. 75, 90, yes.
Out of that list, only 57 is composite.
9 and 10 are but 11 is prime
99 is composite because it is divisible by 9 and 11
253 is a composite number. It is equal to 11 x 23.
11
yes, it is divisible by 9 and 23
Of those odd numbers, only 57 is composite.
Yes. Its factors are: 1, 11, 23, 253.
9 is the composite number. the factors are: 1,3 and 9. all the rest are prime.
Out of that list, 9 and 15 is a composite.
20, yes. The rest, no.