A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 2930256 can be evenly divided by 1 2 3 4 6 7 8 9 12 14 16 17 18 19 21 24 27 28 34 36 38 42 48 51 54 56 57 63 68 72 76 81 84 102 108 112 114 119 126 133 136 144 152 153 162 168 171 189 204 216 228 238 252 266 272 304 306 323 324 336 342 357 378 399 408 432 456 459 476 504 513 532 567 612 646 648 684 714 756 798 816 912 918 952 969 1,008 1,026 1,064 1,071 1,134 1,197 1,224 1,292 1,296 1,368 1,377 1,428 1,512 1,539 1,596 1,836 1,904 1,938 2,052 2,128 2,142 2,261 2,268 2,394 2,448 2,584 2,736 2,754 2,856 2,907 3,024 3,078 3,192 3,213 3,591 3,672 3,876 4,104 4,284 4,522 4,536 4,788 5,168 5,508 5,712 5,814 6,156 6,384 6,426 6,783 7,182 7,344 7,752 8,208 8,568 8,721 9,044 9,072 9,576 9,639 10,773 11,016 11,628 12,312 12,852 13,566 14,364 15,504 17,136 17,442 18,088 19,152 19,278 20,349 21,546 22,032 23,256 24,624 25,704 26,163 27,132 28,728 34,884 36,176 38,556 40,698 43,092 46,512 51,408 52,326 54,264 57,456 61,047 69,768 77,112 81,396 86,184 104,652 108,528 122,094 139,536 154,224 162,792 172,368 183,141 209,304 244,188 325,584 366,282 418,608 488,376 732,564 976,752 1,465,128 and 2,930,256, with no remainder.
Since 2,930,256 cannot be divided by just 1 and 2,930,256, it is not a prime number.