Q: Is 21,872 a Prime Number?
A: No, 21,872 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 21872 can be evenly divided by 1 2 4 8 16 1,367 2,734 5,468 10,936 and 21,872, with no remainder.
Since 21,872 cannot be divided by just 1 and 21,872, it is not a prime number.