A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 5043840 can be evenly divided by 1 2 3 4 5 6 8 10 12 15 16 20 24 30 32 37 40 48 60 64 71 74 80 96 111 120 128 142 148 160 185 192 213 222 240 284 296 320 355 370 384 426 444 480 555 568 592 640 710 740 852 888 960 1,065 1,110 1,136 1,184 1,420 1,480 1,704 1,776 1,920 2,130 2,220 2,272 2,368 2,627 2,840 2,960 3,408 3,552 4,260 4,440 4,544 4,736 5,254 5,680 5,920 6,816 7,104 7,881 8,520 8,880 9,088 10,508 11,360 11,840 13,135 13,632 14,208 15,762 17,040 17,760 21,016 22,720 23,680 26,270 27,264 31,524 34,080 35,520 39,405 42,032 45,440 52,540 63,048 68,160 71,040 78,810 84,064 105,080 126,096 136,320 157,620 168,128 210,160 252,192 315,240 336,256 420,320 504,384 630,480 840,640 1,008,768 1,260,960 1,681,280 2,521,920 and 5,043,840, with no remainder.
Since 5,043,840 cannot be divided by just 1 and 5,043,840, it is not a prime number.