A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 6270144 can be evenly divided by 1 2 3 4 6 8 12 16 17 24 32 34 48 51 64 68 96 102 113 136 192 204 226 272 289 339 408 452 544 578 678 816 867 904 1,088 1,156 1,356 1,632 1,734 1,808 1,921 2,312 2,712 3,264 3,468 3,616 3,842 4,624 5,424 5,763 6,936 7,232 7,684 9,248 10,848 11,526 13,872 15,368 18,496 21,696 23,052 27,744 30,736 32,657 46,104 55,488 61,472 65,314 92,208 97,971 122,944 130,628 184,416 195,942 261,256 368,832 391,884 522,512 783,768 1,045,024 1,567,536 2,090,048 3,135,072 and 6,270,144, with no remainder.
Since 6,270,144 cannot be divided by just 1 and 6,270,144, it is not a prime number.