A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 8749818 can be evenly divided by 1 2 3 6 7 9 11 14 18 21 22 33 42 59 63 66 77 99 107 118 126 154 177 198 214 231 321 354 413 462 531 642 649 693 749 826 963 1,062 1,177 1,239 1,298 1,386 1,498 1,926 1,947 2,247 2,354 2,478 3,531 3,717 3,894 4,494 4,543 5,841 6,313 6,741 7,062 7,434 8,239 9,086 10,593 11,682 12,626 13,482 13,629 16,478 18,939 21,186 24,717 27,258 37,878 40,887 44,191 49,434 56,817 69,443 74,151 81,774 88,382 113,634 132,573 138,886 148,302 208,329 265,146 397,719 416,658 486,101 624,987 795,438 972,202 1,249,974 1,458,303 2,916,606 4,374,909 and 8,749,818, with no remainder.
Since 8,749,818 cannot be divided by just 1 and 8,749,818, it is not a prime number.