A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 844200 can be evenly divided by 1 2 3 4 5 6 7 8 9 10 12 14 15 18 20 21 24 25 28 30 35 36 40 42 45 50 56 60 63 67 70 72 75 84 90 100 105 120 126 134 140 150 168 175 180 200 201 210 225 252 268 280 300 315 335 350 360 402 420 450 469 504 525 536 600 603 630 670 700 804 840 900 938 1,005 1,050 1,206 1,260 1,340 1,400 1,407 1,575 1,608 1,675 1,800 1,876 2,010 2,100 2,345 2,412 2,520 2,680 2,814 3,015 3,150 3,350 3,752 4,020 4,200 4,221 4,690 4,824 5,025 5,628 6,030 6,300 6,700 7,035 8,040 8,442 9,380 10,050 11,256 11,725 12,060 12,600 13,400 14,070 15,075 16,884 18,760 20,100 21,105 23,450 24,120 28,140 30,150 33,768 35,175 40,200 42,210 46,900 56,280 60,300 70,350 84,420 93,800 105,525 120,600 140,700 168,840 211,050 281,400 422,100 and 844,200, with no remainder.
Since 844,200 cannot be divided by just 1 and 844,200, it is not a prime number.