A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 6308064 can be evenly divided by 1 2 3 4 6 7 8 9 12 14 16 18 21 24 27 28 32 36 42 48 49 54 56 63 72 84 96 98 108 112 126 144 147 149 168 189 196 216 224 252 288 294 298 336 378 392 432 441 447 504 588 596 672 756 784 864 882 894 1,008 1,043 1,176 1,192 1,323 1,341 1,512 1,568 1,764 1,788 2,016 2,086 2,352 2,384 2,646 2,682 3,024 3,129 3,528 3,576 4,023 4,172 4,704 4,768 5,292 5,364 6,048 6,258 7,056 7,152 7,301 8,046 8,344 9,387 10,584 10,728 12,516 14,112 14,304 14,602 16,092 16,688 18,774 21,168 21,456 21,903 25,032 28,161 29,204 32,184 33,376 37,548 42,336 42,912 43,806 50,064 56,322 58,408 64,368 65,709 75,096 87,612 100,128 112,644 116,816 128,736 131,418 150,192 175,224 197,127 225,288 233,632 262,836 300,384 350,448 394,254 450,576 525,672 700,896 788,508 901,152 1,051,344 1,577,016 2,102,688 3,154,032 and 6,308,064, with no remainder.
Since 6,308,064 cannot be divided by just 1 and 6,308,064, it is not a prime number.