A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 4393752 can be evenly divided by 1 2 3 4 6 8 11 12 17 22 24 33 34 44 51 66 68 88 89 102 121 132 136 178 187 204 242 264 267 356 363 374 408 484 534 561 712 726 748 968 979 1,068 1,122 1,452 1,496 1,513 1,958 2,057 2,136 2,244 2,904 2,937 3,026 3,916 4,114 4,488 4,539 5,874 6,052 6,171 7,832 8,228 9,078 10,769 11,748 12,104 12,342 16,456 16,643 18,156 21,538 23,496 24,684 32,307 33,286 36,312 43,076 49,368 49,929 64,614 66,572 86,152 99,858 129,228 133,144 183,073 199,716 258,456 366,146 399,432 549,219 732,292 1,098,438 1,464,584 2,196,876 and 4,393,752, with no remainder.
Since 4,393,752 cannot be divided by just 1 and 4,393,752, it is not a prime number.