A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 885600 can be evenly divided by 1 2 3 4 5 6 8 9 10 12 15 16 18 20 24 25 27 30 32 36 40 41 45 48 50 54 60 72 75 80 82 90 96 100 108 120 123 135 144 150 160 164 180 200 205 216 225 240 246 270 288 300 328 360 369 400 410 432 450 480 492 540 600 615 656 675 720 738 800 820 864 900 984 1,025 1,080 1,107 1,200 1,230 1,312 1,350 1,440 1,476 1,640 1,800 1,845 1,968 2,050 2,160 2,214 2,400 2,460 2,700 2,952 3,075 3,280 3,600 3,690 3,936 4,100 4,320 4,428 4,920 5,400 5,535 5,904 6,150 6,560 7,200 7,380 8,200 8,856 9,225 9,840 10,800 11,070 11,808 12,300 14,760 16,400 17,712 18,450 19,680 21,600 22,140 24,600 27,675 29,520 32,800 35,424 36,900 44,280 49,200 55,350 59,040 73,800 88,560 98,400 110,700 147,600 177,120 221,400 295,200 442,800 and 885,600, with no remainder.
Since 885,600 cannot be divided by just 1 and 885,600, it is not a prime number.