A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 4521696 can be evenly divided by 1 2 3 4 6 8 12 16 19 24 32 37 38 48 57 67 74 76 96 111 114 134 148 152 201 222 228 268 296 304 402 444 456 536 592 608 703 804 888 912 1,072 1,184 1,273 1,406 1,608 1,776 1,824 2,109 2,144 2,479 2,546 2,812 3,216 3,552 3,819 4,218 4,958 5,092 5,624 6,432 7,437 7,638 8,436 9,916 10,184 11,248 14,874 15,276 16,872 19,832 20,368 22,496 29,748 30,552 33,744 39,664 40,736 47,101 59,496 61,104 67,488 79,328 94,202 118,992 122,208 141,303 188,404 237,984 282,606 376,808 565,212 753,616 1,130,424 1,507,232 2,260,848 and 4,521,696, with no remainder.
Since 4,521,696 cannot be divided by just 1 and 4,521,696, it is not a prime number.