A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 4293520 can be evenly divided by 1 2 4 5 7 8 10 11 14 16 17 20 22 28 34 35 40 41 44 55 56 68 70 77 80 82 85 88 110 112 119 136 140 154 164 170 176 187 205 220 238 272 280 287 308 328 340 374 385 410 440 451 476 560 574 595 616 656 680 697 748 770 820 880 902 935 952 1,148 1,190 1,232 1,309 1,360 1,394 1,435 1,496 1,540 1,640 1,804 1,870 1,904 2,255 2,296 2,380 2,618 2,788 2,870 2,992 3,080 3,157 3,280 3,485 3,608 3,740 4,510 4,592 4,760 4,879 5,236 5,576 5,740 6,160 6,314 6,545 6,970 7,216 7,480 7,667 9,020 9,520 9,758 10,472 11,152 11,480 12,628 13,090 13,940 14,960 15,334 15,785 18,040 19,516 20,944 22,960 24,395 25,256 26,180 27,880 30,668 31,570 36,080 38,335 39,032 48,790 50,512 52,360 53,669 55,760 61,336 63,140 76,670 78,064 97,580 104,720 107,338 122,672 126,280 153,340 195,160 214,676 252,560 268,345 306,680 390,320 429,352 536,690 613,360 858,704 1,073,380 2,146,760 and 4,293,520, with no remainder.
Since 4,293,520 cannot be divided by just 1 and 4,293,520, it is not a prime number.