A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 8861400 can be evenly divided by 1 2 3 4 5 6 8 9 10 12 15 18 20 24 25 27 30 36 40 45 50 54 60 72 75 81 90 100 108 120 135 150 162 180 200 216 225 270 300 324 360 405 450 540 547 600 648 675 810 900 1,080 1,094 1,350 1,620 1,641 1,800 2,025 2,188 2,700 2,735 3,240 3,282 4,050 4,376 4,923 5,400 5,470 6,564 8,100 8,205 9,846 10,940 13,128 13,675 14,769 16,200 16,410 19,692 21,880 24,615 27,350 29,538 32,820 39,384 41,025 44,307 49,230 54,700 59,076 65,640 73,845 82,050 88,614 98,460 109,400 118,152 123,075 147,690 164,100 177,228 196,920 221,535 246,150 295,380 328,200 354,456 369,225 443,070 492,300 590,760 738,450 886,140 984,600 1,107,675 1,476,900 1,772,280 2,215,350 2,953,800 4,430,700 and 8,861,400, with no remainder.
Since 8,861,400 cannot be divided by just 1 and 8,861,400, it is not a prime number.