A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 7734672 can be evenly divided by 1 2 3 4 6 8 9 11 12 16 18 19 22 24 33 36 38 44 48 57 66 72 76 88 99 114 132 144 152 171 176 198 209 228 257 264 304 342 396 418 456 514 528 627 684 771 792 836 912 1,028 1,254 1,368 1,542 1,584 1,672 1,881 2,056 2,313 2,508 2,736 2,827 3,084 3,344 3,762 4,112 4,626 4,883 5,016 5,654 6,168 7,524 8,481 9,252 9,766 10,032 11,308 12,336 14,649 15,048 16,962 18,504 19,532 22,616 25,443 29,298 30,096 33,924 37,008 39,064 43,947 45,232 50,886 53,713 58,596 67,848 78,128 87,894 101,772 107,426 117,192 135,696 161,139 175,788 203,544 214,852 234,384 322,278 351,576 407,088 429,704 483,417 644,556 703,152 859,408 966,834 1,289,112 1,933,668 2,578,224 3,867,336 and 7,734,672, with no remainder.
Since 7,734,672 cannot be divided by just 1 and 7,734,672, it is not a prime number.