Q: Is 2,561,728 a Prime Number?
A: No, 2,561,728 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 2561728 can be evenly divided by 1 2 4 8 13 16 26 32 52 64 104 208 416 832 3,079 6,158 12,316 24,632 40,027 49,264 80,054 98,528 160,108 197,056 320,216 640,432 1,280,864 and 2,561,728, with no remainder.
Since 2,561,728 cannot be divided by just 1 and 2,561,728, it is not a prime number.