A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 634752 can be evenly divided by 1 2 3 4 6 8 9 12 16 18 19 24 29 32 36 38 48 57 58 64 72 76 87 96 114 116 128 144 152 171 174 192 228 232 261 288 304 342 348 384 456 464 522 551 576 608 684 696 912 928 1,044 1,102 1,152 1,216 1,368 1,392 1,653 1,824 1,856 2,088 2,204 2,432 2,736 2,784 3,306 3,648 3,712 4,176 4,408 4,959 5,472 5,568 6,612 7,296 8,352 8,816 9,918 10,944 11,136 13,224 16,704 17,632 19,836 21,888 26,448 33,408 35,264 39,672 52,896 70,528 79,344 105,792 158,688 211,584 317,376 and 634,752, with no remainder.
Since 634,752 cannot be divided by just 1 and 634,752, it is not a prime number.