Q: Is 21,311 a Prime Number?
A: No, 21,311 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 21311 can be evenly divided by 1 101 211 and 21,311, with no remainder.
Since 21,311 cannot be divided by just 1 and 21,311, it is not a prime number.