Q: Is 21,791 a Prime Number?
A: No, 21,791 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 21791 can be evenly divided by 1 7 11 77 283 1,981 3,113 and 21,791, with no remainder.
Since 21,791 cannot be divided by just 1 and 21,791, it is not a prime number.