13 and 19.
They are 13 and 19
247 is not prime. 247 = 13 * 19
prime numbers above 13 = 17, 19, 23, 29, 31,...
They are: 11, 13, 17 and 19
13 and 19.
They are 13 and 19
19 is prime.
13 and 19 are prime. 33 and 45 are composite.
13 is prime 14=2x7, 2 factors 15=3x5, 2 factors 16=24, 4 factors 17 is prime 18=2x32, 3 factors 19 is prime So the answer is 3 (14, 15 and 16)
247 is not prime. 247 = 13 * 19
13,19.
Even number bigger than two are never prime so cross them out, leaving11,13,15,17,19Any number ending in 5 is divisible by 5 and so can not be prime,This leaves 11,13,17,19 which all could be prime and actually are.
prime numbers above 13 = 17, 19, 23, 29, 31,...
39 is not a prime number. It can be divided by 3 and 13.
They are: 11, 13, 17 and 19
8143144792574020282236217021 is not prime. 8143144792574020282236217021 = 13 * 19 * 61 * 631 * 856517044004715575473