Q: Is 661,561 a Prime Number?
A: No, 661,561 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 661561 can be evenly divided by 1 19 34,819 and 661,561, with no remainder.
Since 661,561 cannot be divided by just 1 and 661,561, it is not a prime number.