A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 2891952 can be evenly divided by 1 2 3 4 6 7 8 9 12 14 16 18 19 21 24 28 36 38 42 48 56 57 63 72 76 84 112 114 126 133 144 151 152 168 171 228 252 266 302 304 336 342 399 453 456 504 532 604 684 798 906 912 1,008 1,057 1,064 1,197 1,208 1,359 1,368 1,596 1,812 2,114 2,128 2,394 2,416 2,718 2,736 2,869 3,171 3,192 3,624 4,228 4,788 5,436 5,738 6,342 6,384 7,248 8,456 8,607 9,513 9,576 10,872 11,476 12,684 16,912 17,214 19,026 19,152 20,083 21,744 22,952 25,368 25,821 34,428 38,052 40,166 45,904 50,736 51,642 60,249 68,856 76,104 80,332 103,284 120,498 137,712 152,208 160,664 180,747 206,568 240,996 321,328 361,494 413,136 481,992 722,988 963,984 1,445,976 and 2,891,952, with no remainder.
Since 2,891,952 cannot be divided by just 1 and 2,891,952, it is not a prime number.