A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 8863470 can be evenly divided by 1 2 3 5 6 7 9 10 11 14 15 18 21 22 30 33 35 42 45 55 63 66 70 77 90 99 105 110 126 154 165 198 210 231 315 330 385 462 495 630 693 770 990 1,155 1,279 1,386 2,310 2,558 3,465 3,837 6,395 6,930 7,674 8,953 11,511 12,790 14,069 17,906 19,185 23,022 26,859 28,138 38,370 42,207 44,765 53,718 57,555 70,345 80,577 84,414 89,530 98,483 115,110 126,621 134,295 140,690 161,154 196,966 211,035 253,242 268,590 295,449 402,885 422,070 492,415 590,898 633,105 805,770 886,347 984,830 1,266,210 1,477,245 1,772,694 2,954,490 4,431,735 and 8,863,470, with no remainder.
Since 8,863,470 cannot be divided by just 1 and 8,863,470, it is not a prime number.