A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 3352752 can be evenly divided by 1 2 3 4 6 8 9 12 13 16 18 24 26 27 36 39 48 52 54 72 78 81 104 108 117 144 156 162 199 208 216 234 312 324 351 398 432 468 597 624 648 702 796 936 1,053 1,194 1,296 1,404 1,592 1,791 1,872 2,106 2,388 2,587 2,808 3,184 3,582 4,212 4,776 5,174 5,373 5,616 7,164 7,761 8,424 9,552 10,348 10,746 14,328 15,522 16,119 16,848 20,696 21,492 23,283 28,656 31,044 32,238 41,392 42,984 46,566 62,088 64,476 69,849 85,968 93,132 124,176 128,952 139,698 186,264 209,547 257,904 279,396 372,528 419,094 558,792 838,188 1,117,584 1,676,376 and 3,352,752, with no remainder.
Since 3,352,752 cannot be divided by just 1 and 3,352,752, it is not a prime number.