A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 8493264 can be evenly divided by 1 2 3 4 6 8 9 12 13 16 18 24 26 36 39 48 52 72 78 104 117 144 156 169 208 234 312 338 349 468 507 624 676 698 936 1,014 1,047 1,352 1,396 1,521 1,872 2,028 2,094 2,704 2,792 3,042 3,141 4,056 4,188 4,537 5,584 6,084 6,282 8,112 8,376 9,074 12,168 12,564 13,611 16,752 18,148 24,336 25,128 27,222 36,296 40,833 50,256 54,444 58,981 72,592 81,666 108,888 117,962 163,332 176,943 217,776 235,924 326,664 353,886 471,848 530,829 653,328 707,772 943,696 1,061,658 1,415,544 2,123,316 2,831,088 4,246,632 and 8,493,264, with no remainder.
Since 8,493,264 cannot be divided by just 1 and 8,493,264, it is not a prime number.