A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 3490344 can be evenly divided by 1 2 3 4 6 8 9 11 12 13 18 22 24 26 27 33 36 39 44 52 54 66 72 78 88 99 104 108 113 117 132 143 156 198 216 226 234 264 286 297 312 339 351 396 429 452 468 572 594 678 702 792 858 904 936 1,017 1,144 1,188 1,243 1,287 1,356 1,404 1,469 1,716 2,034 2,376 2,486 2,574 2,712 2,808 2,938 3,051 3,432 3,729 3,861 4,068 4,407 4,972 5,148 5,876 6,102 7,458 7,722 8,136 8,814 9,944 10,296 11,187 11,752 12,204 13,221 14,916 15,444 16,159 17,628 22,374 24,408 26,442 29,832 30,888 32,318 33,561 35,256 39,663 44,748 48,477 52,884 64,636 67,122 79,326 89,496 96,954 105,768 129,272 134,244 145,431 158,652 193,908 268,488 290,862 317,304 387,816 436,293 581,724 872,586 1,163,448 1,745,172 and 3,490,344, with no remainder.
Since 3,490,344 cannot be divided by just 1 and 3,490,344, it is not a prime number.