A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 2072304 can be evenly divided by 1 2 3 4 6 8 9 12 13 16 18 24 26 27 36 39 41 48 52 54 72 78 81 82 104 108 117 123 144 156 162 164 208 216 234 243 246 312 324 328 351 369 432 468 486 492 533 624 648 656 702 738 936 972 984 1,053 1,066 1,107 1,296 1,404 1,476 1,599 1,872 1,944 1,968 2,106 2,132 2,214 2,808 2,952 3,159 3,198 3,321 3,888 4,212 4,264 4,428 4,797 5,616 5,904 6,318 6,396 6,642 8,424 8,528 8,856 9,594 9,963 12,636 12,792 13,284 14,391 16,848 17,712 19,188 19,926 25,272 25,584 26,568 28,782 38,376 39,852 43,173 50,544 53,136 57,564 76,752 79,704 86,346 115,128 129,519 159,408 172,692 230,256 259,038 345,384 518,076 690,768 1,036,152 and 2,072,304, with no remainder.
Since 2,072,304 cannot be divided by just 1 and 2,072,304, it is not a prime number.