Prime numbers are numbers which can only be divided by 1 and the number itself. Some lists them starting with 1, others 2.
A link to a table of the first 10,000 primes:
https://primes.utm.edu/lists/small/10000.txt
2
Replies sorted oldest to newest
19
37
43
Baz posted:45
Not prime, it divides by 5 as well. 
47
All prime numbers (except for 2) are odd, but not all odd numbers are prime!
53
If in doubt as to if a number is prime check it on that link I have in my opening post.
All odd numbers ending with 5 are divisble by 5 so, other than 5, they cannot be prime.
Any number where the sum of the individual digits is divisible by 3 is itself also divisible by 3 so won't be prime, other than 3, So for 45: 4+5=9 which is divisble by 3 so 45 is divisble by 3 for instance. That only works for 3 and doesn't work for any other number (other than 9).
59
67
73
89
97
103
107
131
)149
157