Answer:
Some prime numbers are
2, 7, 19
(more: 2,3,5,7,11,13,17,19,23,29,31,37,41,43,47...)
Prime numbers are considered to be prime when their factors only include 1 and itself. The factors have to be whole numbers.
2 is the only even prime number. 1x2=2. No other combination will work.
7 is another prime number. 1x7=7. You can also find no other combination of whole numbers that will multiply to equal 7.
19 is another prime number. You cannot find another combination other than 1 and 19.
These are just some examples. There are more prime numbers in the lower numbers because they are less likely to come across a number that will multiply into it.