A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 5145504 can be evenly divided by 1 2 3 4 6 7 8 12 13 14 16 19 21 24 26 28 31 32 38 39 42 48 52 56 57 62 76 78 84 91 93 96 104 112 114 124 133 152 156 168 182 186 208 217 224 228 247 248 266 273 304 312 336 364 372 399 403 416 434 456 494 496 532 546 589 608 624 651 672 728 741 744 798 806 868 912 988 992 1,064 1,092 1,178 1,209 1,248 1,302 1,456 1,482 1,488 1,596 1,612 1,729 1,736 1,767 1,824 1,976 2,128 2,184 2,356 2,418 2,604 2,821 2,912 2,964 2,976 3,192 3,224 3,458 3,472 3,534 3,952 4,123 4,256 4,368 4,712 4,836 5,187 5,208 5,642 5,928 6,384 6,448 6,916 6,944 7,068 7,657 7,904 8,246 8,463 8,736 9,424 9,672 10,374 10,416 11,284 11,856 12,369 12,768 12,896 13,832 14,136 15,314 16,492 16,926 18,848 19,344 20,748 20,832 22,568 22,971 23,712 24,738 27,664 28,272 30,628 32,984 33,852 38,688 41,496 45,136 45,942 49,476 53,599 55,328 56,544 61,256 65,968 67,704 82,992 90,272 91,884 98,952 107,198 122,512 131,936 135,408 160,797 165,984 183,768 197,904 214,396 245,024 270,816 321,594 367,536 395,808 428,792 643,188 735,072 857,584 1,286,376 1,715,168 2,572,752 and 5,145,504, with no remainder.
Since 5,145,504 cannot be divided by just 1 and 5,145,504, it is not a prime number.