A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 8428200 can be evenly divided by 1 2 3 4 5 6 8 10 11 12 15 20 22 24 25 30 33 40 44 50 55 60 66 75 88 100 110 120 132 150 165 200 220 264 275 300 330 440 550 600 660 825 1,100 1,277 1,320 1,650 2,200 2,554 3,300 3,831 5,108 6,385 6,600 7,662 10,216 12,770 14,047 15,324 19,155 25,540 28,094 30,648 31,925 38,310 42,141 51,080 56,188 63,850 70,235 76,620 84,282 95,775 112,376 127,700 140,470 153,240 168,564 191,550 210,705 255,400 280,940 337,128 351,175 383,100 421,410 561,880 702,350 766,200 842,820 1,053,525 1,404,700 1,685,640 2,107,050 2,809,400 4,214,100 and 8,428,200, with no remainder.
Since 8,428,200 cannot be divided by just 1 and 8,428,200, it is not a prime number.