Q: Is 685,720 a Prime Number?
A: No, 685,720 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 685720 can be evenly divided by 1 2 4 5 7 8 10 14 20 28 31 35 40 56 62 70 79 124 140 155 158 217 248 280 310 316 395 434 553 620 632 790 868 1,085 1,106 1,240 1,580 1,736 2,170 2,212 2,449 2,765 3,160 4,340 4,424 4,898 5,530 8,680 9,796 11,060 12,245 17,143 19,592 22,120 24,490 34,286 48,980 68,572 85,715 97,960 137,144 171,430 342,860 and 685,720, with no remainder.
Since 685,720 cannot be divided by just 1 and 685,720, it is not a prime number.