A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 2268960 can be evenly divided by 1 2 3 4 5 6 8 10 12 15 16 20 24 29 30 32 40 48 58 60 80 87 96 116 120 145 160 163 174 232 240 290 326 348 435 464 480 489 580 652 696 815 870 928 978 1,160 1,304 1,392 1,630 1,740 1,956 2,320 2,445 2,608 2,784 3,260 3,480 3,912 4,640 4,727 4,890 5,216 6,520 6,960 7,824 9,454 9,780 13,040 13,920 14,181 15,648 18,908 19,560 23,635 26,080 28,362 37,816 39,120 47,270 56,724 70,905 75,632 78,240 94,540 113,448 141,810 151,264 189,080 226,896 283,620 378,160 453,792 567,240 756,320 1,134,480 and 2,268,960, with no remainder.
Since 2,268,960 cannot be divided by just 1 and 2,268,960, it is not a prime number.