Q: Is 21,740 a Prime Number?
A: No, 21,740 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 21740 can be evenly divided by 1 2 4 5 10 20 1,087 2,174 4,348 5,435 10,870 and 21,740, with no remainder.
Since 21,740 cannot be divided by just 1 and 21,740, it is not a prime number.