A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 4243680 can be evenly divided by 1 2 3 4 5 6 7 8 9 10 12 14 15 16 18 20 21 24 28 30 32 35 36 40 42 45 48 56 60 63 70 72 80 84 90 96 105 112 120 126 140 144 160 168 180 210 224 240 252 280 288 315 336 360 420 421 480 504 560 630 672 720 840 842 1,008 1,120 1,260 1,263 1,440 1,680 1,684 2,016 2,105 2,520 2,526 2,947 3,360 3,368 3,789 4,210 5,040 5,052 5,894 6,315 6,736 7,578 8,420 8,841 10,080 10,104 11,788 12,630 13,472 14,735 15,156 16,840 17,682 18,945 20,208 23,576 25,260 26,523 29,470 30,312 33,680 35,364 37,890 40,416 44,205 47,152 50,520 53,046 58,940 60,624 67,360 70,728 75,780 88,410 94,304 101,040 106,092 117,880 121,248 132,615 141,456 151,560 176,820 202,080 212,184 235,760 265,230 282,912 303,120 353,640 424,368 471,520 530,460 606,240 707,280 848,736 1,060,920 1,414,560 2,121,840 and 4,243,680, with no remainder.
Since 4,243,680 cannot be divided by just 1 and 4,243,680, it is not a prime number.