Q: Is 21,040 a Prime Number?
A: No, 21,040 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 21040 can be evenly divided by 1 2 4 5 8 10 16 20 40 80 263 526 1,052 1,315 2,104 2,630 4,208 5,260 10,520 and 21,040, with no remainder.
Since 21,040 cannot be divided by just 1 and 21,040, it is not a prime number.