Q: Is 21,817 a Prime Number?
A: Yes, 21,817 is a prime number.
A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 21817 can be evenly divided by 1 and 21,817, with no remainder.
Since 21,817 can be divided by just 1 and 21,817, it is a prime number.