Q: Is 21,501 a Prime Number?
A: No, 21,501 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 21501 can be evenly divided by 1 3 9 2,389 7,167 and 21,501, with no remainder.
Since 21,501 cannot be divided by just 1 and 21,501, it is not a prime number.