A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 8152326 can be evenly divided by 1 2 3 6 7 9 13 14 18 21 26 27 39 42 49 54 63 78 79 81 91 98 117 126 147 158 162 182 189 234 237 273 294 351 378 441 474 546 553 567 637 702 711 819 882 1,027 1,053 1,106 1,134 1,274 1,323 1,422 1,638 1,659 1,911 2,054 2,106 2,133 2,457 2,646 3,081 3,318 3,822 3,871 3,969 4,266 4,914 4,977 5,733 6,162 6,399 7,189 7,371 7,742 7,938 9,243 9,954 11,466 11,613 12,798 14,378 14,742 14,931 17,199 18,486 21,567 23,226 27,729 29,862 34,398 34,839 43,134 44,793 50,323 51,597 55,458 64,701 69,678 83,187 89,586 100,646 103,194 104,517 129,402 150,969 166,374 194,103 209,034 301,938 313,551 388,206 452,907 582,309 627,102 905,814 1,164,618 1,358,721 2,717,442 4,076,163 and 8,152,326, with no remainder.
Since 8,152,326 cannot be divided by just 1 and 8,152,326, it is not a prime number.