A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 6685632 can be evenly divided by 1 2 3 4 6 8 9 12 16 18 24 27 32 36 48 53 54 64 72 73 96 106 108 144 146 159 192 212 216 219 288 292 318 424 432 438 477 576 584 636 657 848 864 876 954 1,168 1,272 1,314 1,431 1,696 1,728 1,752 1,908 1,971 2,336 2,544 2,628 2,862 3,392 3,504 3,816 3,869 3,942 4,672 5,088 5,256 5,724 7,008 7,632 7,738 7,884 10,176 10,512 11,448 11,607 14,016 15,264 15,476 15,768 21,024 22,896 23,214 30,528 30,952 31,536 34,821 42,048 45,792 46,428 61,904 63,072 69,642 91,584 92,856 104,463 123,808 126,144 139,284 185,712 208,926 247,616 278,568 371,424 417,852 557,136 742,848 835,704 1,114,272 1,671,408 2,228,544 3,342,816 and 6,685,632, with no remainder.
Since 6,685,632 cannot be divided by just 1 and 6,685,632, it is not a prime number.