A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 8171136 can be evenly divided by 1 2 3 4 6 8 9 12 16 18 24 32 36 41 48 64 72 82 96 123 128 144 164 173 192 246 288 328 346 369 384 492 519 576 656 692 738 984 1,038 1,152 1,312 1,384 1,476 1,557 1,968 2,076 2,624 2,768 2,952 3,114 3,936 4,152 5,248 5,536 5,904 6,228 7,093 7,872 8,304 11,072 11,808 12,456 14,186 15,744 16,608 21,279 22,144 23,616 24,912 28,372 33,216 42,558 47,232 49,824 56,744 63,837 66,432 85,116 99,648 113,488 127,674 170,232 199,296 226,976 255,348 340,464 453,952 510,696 680,928 907,904 1,021,392 1,361,856 2,042,784 2,723,712 4,085,568 and 8,171,136, with no remainder.
Since 8,171,136 cannot be divided by just 1 and 8,171,136, it is not a prime number.