Q: Is 561,664 a Prime Number?
A: No, 561,664 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 561664 can be evenly divided by 1 2 4 8 16 32 64 128 256 512 1,097 2,194 4,388 8,776 17,552 35,104 70,208 140,416 280,832 and 561,664, with no remainder.
Since 561,664 cannot be divided by just 1 and 561,664, it is not a prime number.