A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 6464700 can be evenly divided by 1 2 3 4 5 6 9 10 11 12 15 18 20 22 25 30 33 36 44 45 50 55 60 66 75 90 99 100 110 132 150 165 180 198 220 225 275 300 330 396 450 495 550 653 660 825 900 990 1,100 1,306 1,650 1,959 1,980 2,475 2,612 3,265 3,300 3,918 4,950 5,877 6,530 7,183 7,836 9,795 9,900 11,754 13,060 14,366 16,325 19,590 21,549 23,508 28,732 29,385 32,650 35,915 39,180 43,098 48,975 58,770 64,647 65,300 71,830 86,196 97,950 107,745 117,540 129,294 143,660 146,925 179,575 195,900 215,490 258,588 293,850 323,235 359,150 430,980 538,725 587,700 646,470 718,300 1,077,450 1,292,940 1,616,175 2,154,900 3,232,350 and 6,464,700, with no remainder.
Since 6,464,700 cannot be divided by just 1 and 6,464,700, it is not a prime number.