Q: Is 2,561,521 a Prime Number?
A: Yes, 2,561,521 is a prime number.
A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 2561521 can be evenly divided by 1 and 2,561,521, with no remainder.
Since 2,561,521 can be divided by just 1 and 2,561,521, it is a prime number.