A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 3401244 can be evenly divided by 1 2 3 4 6 7 9 11 12 14 18 21 22 27 28 33 36 42 44 54 63 66 77 84 99 108 126 132 154 189 198 231 252 297 308 378 396 409 462 594 693 756 818 924 1,188 1,227 1,386 1,636 2,079 2,454 2,772 2,863 3,681 4,158 4,499 4,908 5,726 7,362 8,316 8,589 8,998 11,043 11,452 13,497 14,724 17,178 17,996 22,086 25,767 26,994 31,493 34,356 40,491 44,172 51,534 53,988 62,986 77,301 80,982 94,479 103,068 121,473 125,972 154,602 161,964 188,958 242,946 283,437 309,204 377,916 485,892 566,874 850,311 1,133,748 1,700,622 and 3,401,244, with no remainder.
Since 3,401,244 cannot be divided by just 1 and 3,401,244, it is not a prime number.