A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 6367320 can be evenly divided by 1 2 3 4 5 6 8 9 10 12 15 18 20 23 24 30 36 40 45 46 60 69 72 90 92 115 120 138 180 184 207 230 276 345 360 414 460 552 690 769 828 920 1,035 1,380 1,538 1,656 2,070 2,307 2,760 3,076 3,845 4,140 4,614 6,152 6,921 7,690 8,280 9,228 11,535 13,842 15,380 17,687 18,456 23,070 27,684 30,760 34,605 35,374 46,140 53,061 55,368 69,210 70,748 88,435 92,280 106,122 138,420 141,496 159,183 176,870 212,244 265,305 276,840 318,366 353,740 424,488 530,610 636,732 707,480 795,915 1,061,220 1,273,464 1,591,830 2,122,440 3,183,660 and 6,367,320, with no remainder.
Since 6,367,320 cannot be divided by just 1 and 6,367,320, it is not a prime number.