A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 2031744 can be evenly divided by 1 2 3 4 6 8 11 12 13 16 22 24 26 32 33 37 39 44 48 52 64 66 74 78 88 96 104 111 128 132 143 148 156 176 192 208 222 264 286 296 312 352 384 407 416 429 444 481 528 572 592 624 704 814 832 858 888 962 1,056 1,144 1,184 1,221 1,248 1,408 1,443 1,628 1,664 1,716 1,776 1,924 2,112 2,288 2,368 2,442 2,496 2,886 3,256 3,432 3,552 3,848 4,224 4,576 4,736 4,884 4,992 5,291 5,772 6,512 6,864 7,104 7,696 9,152 9,768 10,582 11,544 13,024 13,728 14,208 15,392 15,873 18,304 19,536 21,164 23,088 26,048 27,456 30,784 31,746 39,072 42,328 46,176 52,096 54,912 61,568 63,492 78,144 84,656 92,352 126,984 156,288 169,312 184,704 253,968 338,624 507,936 677,248 1,015,872 and 2,031,744, with no remainder.
Since 2,031,744 cannot be divided by just 1 and 2,031,744, it is not a prime number.