Q: Is 21,520 a Prime Number?
A: No, 21,520 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 21520 can be evenly divided by 1 2 4 5 8 10 16 20 40 80 269 538 1,076 1,345 2,152 2,690 4,304 5,380 10,760 and 21,520, with no remainder.
Since 21,520 cannot be divided by just 1 and 21,520, it is not a prime number.