A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 703080 can be evenly divided by 1 2 3 4 5 6 7 8 9 10 12 14 15 18 20 21 24 27 28 30 31 35 36 40 42 45 54 56 60 62 63 70 72 81 84 90 93 105 108 120 124 126 135 140 155 162 168 180 186 189 210 216 217 248 252 270 279 280 310 315 324 360 372 378 405 420 434 465 504 540 558 567 620 630 648 651 744 756 810 837 840 868 930 945 1,080 1,085 1,116 1,134 1,240 1,260 1,302 1,395 1,512 1,620 1,674 1,736 1,860 1,890 1,953 2,170 2,232 2,268 2,511 2,520 2,604 2,790 2,835 3,240 3,255 3,348 3,720 3,780 3,906 4,185 4,340 4,536 5,022 5,208 5,580 5,670 5,859 6,510 6,696 7,560 7,812 8,370 8,680 9,765 10,044 11,160 11,340 11,718 12,555 13,020 15,624 16,740 17,577 19,530 20,088 22,680 23,436 25,110 26,040 29,295 33,480 35,154 39,060 46,872 50,220 58,590 70,308 78,120 87,885 100,440 117,180 140,616 175,770 234,360 351,540 and 703,080, with no remainder.
Since 703,080 cannot be divided by just 1 and 703,080, it is not a prime number.