A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 5248584 can be evenly divided by 1 2 3 4 6 8 9 11 12 18 22 24 27 33 36 44 47 54 66 72 88 94 99 108 132 141 188 198 216 264 282 297 376 396 423 517 564 594 792 846 1,034 1,128 1,188 1,269 1,551 1,692 2,068 2,209 2,376 2,538 3,102 3,384 4,136 4,418 4,653 5,076 6,204 6,627 8,836 9,306 10,152 12,408 13,254 13,959 17,672 18,612 19,881 24,299 26,508 27,918 37,224 39,762 48,598 53,016 55,836 59,643 72,897 79,524 97,196 111,672 119,286 145,794 159,048 194,392 218,691 238,572 291,588 437,382 477,144 583,176 656,073 874,764 1,312,146 1,749,528 2,624,292 and 5,248,584, with no remainder.
Since 5,248,584 cannot be divided by just 1 and 5,248,584, it is not a prime number.