Q: Is 21,553 a Prime Number?
A: No, 21,553 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 21553 can be evenly divided by 1 7 3,079 and 21,553, with no remainder.
Since 21,553 cannot be divided by just 1 and 21,553, it is not a prime number.