A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 1924560 can be evenly divided by 1 2 3 4 5 6 8 9 10 11 12 15 16 18 20 22 24 27 30 33 36 40 44 45 48 54 55 60 66 72 80 81 88 90 99 108 110 120 132 135 144 162 165 176 180 198 216 220 240 243 264 270 297 324 330 360 396 405 432 440 486 495 528 540 594 648 660 720 729 792 810 880 891 972 990 1,080 1,188 1,215 1,296 1,320 1,458 1,485 1,584 1,620 1,782 1,944 1,980 2,160 2,187 2,376 2,430 2,640 2,673 2,916 2,970 3,240 3,564 3,645 3,888 3,960 4,374 4,455 4,752 4,860 5,346 5,832 5,940 6,480 7,128 7,290 7,920 8,019 8,748 8,910 9,720 10,692 10,935 11,664 11,880 13,365 14,256 14,580 16,038 17,496 17,820 19,440 21,384 21,870 23,760 24,057 26,730 29,160 32,076 34,992 35,640 40,095 42,768 43,740 48,114 53,460 58,320 64,152 71,280 80,190 87,480 96,228 106,920 120,285 128,304 160,380 174,960 192,456 213,840 240,570 320,760 384,912 481,140 641,520 962,280 and 1,924,560, with no remainder.
Since 1,924,560 cannot be divided by just 1 and 1,924,560, it is not a prime number.