Q: Is 256,400 a Prime Number?
A: No, 256,400 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 256400 can be evenly divided by 1 2 4 5 8 10 16 20 25 40 50 80 100 200 400 641 1,282 2,564 3,205 5,128 6,410 10,256 12,820 16,025 25,640 32,050 51,280 64,100 128,200 and 256,400, with no remainder.
Since 256,400 cannot be divided by just 1 and 256,400, it is not a prime number.