Q: Is 400,000 a Prime Number?
A: No, 400,000 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 400000 can be evenly divided by 1 2 4 5 8 10 16 20 25 32 40 50 64 80 100 125 128 160 200 250 320 400 500 625 640 800 1,000 1,250 1,600 2,000 2,500 3,125 3,200 4,000 5,000 6,250 8,000 10,000 12,500 16,000 20,000 25,000 40,000 50,000 80,000 100,000 200,000 and 400,000, with no remainder.
Since 400,000 cannot be divided by just 1 and 400,000, it is not a prime number.