A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 6670368 can be evenly divided by 1 2 3 4 6 8 9 12 16 18 19 23 24 32 36 38 46 48 53 57 69 72 76 92 96 106 114 138 144 152 159 171 184 207 212 228 276 288 304 318 342 368 414 424 437 456 477 552 608 636 684 736 828 848 874 912 954 1,007 1,104 1,219 1,272 1,311 1,368 1,656 1,696 1,748 1,824 1,908 2,014 2,208 2,438 2,544 2,622 2,736 3,021 3,312 3,496 3,657 3,816 3,933 4,028 4,876 5,088 5,244 5,472 6,042 6,624 6,992 7,314 7,632 7,866 8,056 9,063 9,752 10,488 10,971 12,084 13,984 14,628 15,264 15,732 16,112 18,126 19,504 20,976 21,942 23,161 24,168 29,256 31,464 32,224 36,252 39,008 41,952 43,884 46,322 48,336 58,512 62,928 69,483 72,504 87,768 92,644 96,672 117,024 125,856 138,966 145,008 175,536 185,288 208,449 277,932 290,016 351,072 370,576 416,898 555,864 741,152 833,796 1,111,728 1,667,592 2,223,456 3,335,184 and 6,670,368, with no remainder.
Since 6,670,368 cannot be divided by just 1 and 6,670,368, it is not a prime number.