Q: Is 521,621 a Prime Number?
A: No, 521,621 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 521621 can be evenly divided by 1 191 2,731 and 521,621, with no remainder.
Since 521,621 cannot be divided by just 1 and 521,621, it is not a prime number.