A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 3672768 can be evenly divided by 1 2 3 4 6 8 11 12 16 22 24 32 33 37 44 47 48 64 66 74 88 94 96 111 132 141 148 176 188 192 222 264 282 296 352 376 407 444 517 528 564 592 704 752 814 888 1,034 1,056 1,128 1,184 1,221 1,504 1,551 1,628 1,739 1,776 2,068 2,112 2,256 2,368 2,442 3,008 3,102 3,256 3,478 3,552 4,136 4,512 4,884 5,217 6,204 6,512 6,956 7,104 8,272 9,024 9,768 10,434 12,408 13,024 13,912 16,544 19,129 19,536 20,868 24,816 26,048 27,824 33,088 38,258 39,072 41,736 49,632 55,648 57,387 76,516 78,144 83,472 99,264 111,296 114,774 153,032 166,944 229,548 306,064 333,888 459,096 612,128 918,192 1,224,256 1,836,384 and 3,672,768, with no remainder.
Since 3,672,768 cannot be divided by just 1 and 3,672,768, it is not a prime number.