A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 8250372 can be evenly divided by 1 2 3 4 6 9 12 13 17 18 26 34 36 39 51 52 61 68 78 102 117 122 153 156 183 204 221 234 244 289 306 366 442 468 549 578 612 663 732 793 867 884 1,037 1,098 1,156 1,326 1,586 1,734 1,989 2,074 2,196 2,379 2,601 2,652 3,111 3,172 3,468 3,757 3,978 4,148 4,758 5,202 6,222 7,137 7,514 7,956 9,333 9,516 10,404 11,271 12,444 13,481 14,274 15,028 17,629 18,666 22,542 26,962 28,548 33,813 35,258 37,332 40,443 45,084 52,887 53,924 67,626 70,516 80,886 105,774 121,329 135,252 158,661 161,772 211,548 229,177 242,658 317,322 458,354 485,316 634,644 687,531 916,708 1,375,062 2,062,593 2,750,124 4,125,186 and 8,250,372, with no remainder.
Since 8,250,372 cannot be divided by just 1 and 8,250,372, it is not a prime number.