Q: Is 643,520 a Prime Number?
A: No, 643,520 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 643520 can be evenly divided by 1 2 4 5 8 10 16 20 32 40 64 80 160 320 2,011 4,022 8,044 10,055 16,088 20,110 32,176 40,220 64,352 80,440 128,704 160,880 321,760 and 643,520, with no remainder.
Since 643,520 cannot be divided by just 1 and 643,520, it is not a prime number.