Q: Is 655,640 a Prime Number?
A: No, 655,640 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 655640 can be evenly divided by 1 2 4 5 8 10 20 37 40 74 148 185 296 370 443 740 886 1,480 1,772 2,215 3,544 4,430 8,860 16,391 17,720 32,782 65,564 81,955 131,128 163,910 327,820 and 655,640, with no remainder.
Since 655,640 cannot be divided by just 1 and 655,640, it is not a prime number.