Q: Is 21,308 a Prime Number?
A: No, 21,308 is not a prime number.
A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 21308 can be evenly divided by 1 2 4 7 14 28 761 1,522 3,044 5,327 10,654 and 21,308, with no remainder.
Since 21,308 cannot be divided by just 1 and 21,308, it is not a prime number.