Zero
39 is not a prime number because it has four factors: 1,3,13,39 and because prime number are numbers who has 2 factors.
a prime number is a number that can only be divided by 1and its self... 1 isnt a prime number but 2, 3, 5, 7, 9, 11 etc... are prime numbers.
23, 37, 79 and 51 (assuming 1851 is a typo, 18 isnt a prime) if not a typo 1851 isnt a prime number anyway, it divides by 3
There isnt one country who invented all the numbers.
Composite
There isnt
There isnt any
Well There Isnt Numbers..
Composite
there isnt one
if you hav a remainder<divide that by 2, wich shud b 1/2. easy? too bad if it isnt. haha!
13 and 3. Isnt it?