A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 4348872 can be evenly divided by 1 2 3 4 6 8 9 11 12 17 18 19 22 24 33 34 36 38 44 51 57 66 68 72 76 88 99 102 114 132 136 152 153 171 187 198 204 209 228 264 289 306 323 342 374 396 408 418 456 561 578 612 627 646 684 748 792 836 867 969 1,122 1,156 1,224 1,254 1,292 1,368 1,496 1,672 1,683 1,734 1,881 1,938 2,244 2,312 2,508 2,584 2,601 2,907 3,179 3,366 3,468 3,553 3,762 3,876 4,488 5,016 5,202 5,491 5,814 6,358 6,732 6,936 7,106 7,524 7,752 9,537 10,404 10,659 10,982 11,628 12,716 13,464 14,212 15,048 16,473 19,074 20,808 21,318 21,964 23,256 25,432 28,424 28,611 31,977 32,946 38,148 42,636 43,928 49,419 57,222 60,401 63,954 65,892 76,296 85,272 98,838 114,444 120,802 127,908 131,784 181,203 197,676 228,888 241,604 255,816 362,406 395,352 483,208 543,609 724,812 1,087,218 1,449,624 2,174,436 and 4,348,872, with no remainder.
Since 4,348,872 cannot be divided by just 1 and 4,348,872, it is not a prime number.