A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 3675672 can be evenly divided by 1 2 3 4 6 7 8 9 11 12 13 14 17 18 21 22 24 26 27 28 33 34 36 39 42 44 51 52 54 56 63 66 68 72 77 78 84 88 91 99 102 104 108 117 119 126 132 136 143 153 154 156 168 182 187 189 198 204 216 221 231 234 238 252 264 273 286 297 306 308 312 351 357 364 374 378 396 408 429 442 459 462 468 476 504 546 561 572 594 612 616 663 693 702 714 728 748 756 792 819 858 884 918 924 936 952 1,001 1,071 1,092 1,122 1,144 1,188 1,224 1,287 1,309 1,326 1,386 1,404 1,428 1,496 1,512 1,547 1,638 1,683 1,716 1,768 1,836 1,848 1,989 2,002 2,079 2,142 2,184 2,244 2,376 2,431 2,457 2,574 2,618 2,652 2,772 2,808 2,856 3,003 3,094 3,213 3,276 3,366 3,432 3,672 3,861 3,927 3,978 4,004 4,158 4,284 4,488 4,641 4,862 4,914 5,049 5,148 5,236 5,304 5,544 5,967 6,006 6,188 6,426 6,552 6,732 7,293 7,722 7,854 7,956 8,008 8,316 8,568 9,009 9,282 9,724 9,828 10,098 10,296 10,472 11,781 11,934 12,012 12,376 12,852 13,464 13,923 14,586 15,444 15,708 15,912 16,632 17,017 18,018 18,564 19,448 19,656 20,196 21,879 23,562 23,868 24,024 25,704 27,027 27,846 29,172 30,888 31,416 34,034 35,343 36,036 37,128 40,392 41,769 43,758 47,124 47,736 51,051 54,054 55,692 58,344 65,637 68,068 70,686 72,072 83,538 87,516 94,248 102,102 108,108 111,384 131,274 136,136 141,372 153,153 167,076 175,032 204,204 216,216 262,548 282,744 306,306 334,152 408,408 459,459 525,096 612,612 918,918 1,225,224 1,837,836 and 3,675,672, with no remainder.
Since 3,675,672 cannot be divided by just 1 and 3,675,672, it is not a prime number.