A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 945120 can be evenly divided by 1 2 3 4 5 6 8 10 11 12 15 16 20 22 24 30 32 33 40 44 48 55 60 66 80 88 96 110 120 132 160 165 176 179 220 240 264 330 352 358 440 480 528 537 660 716 880 895 1,056 1,074 1,320 1,432 1,760 1,790 1,969 2,148 2,640 2,685 2,864 3,580 3,938 4,296 5,280 5,370 5,728 5,907 7,160 7,876 8,592 9,845 10,740 11,814 14,320 15,752 17,184 19,690 21,480 23,628 28,640 29,535 31,504 39,380 42,960 47,256 59,070 63,008 78,760 85,920 94,512 118,140 157,520 189,024 236,280 315,040 472,560 and 945,120, with no remainder.
Since 945,120 cannot be divided by just 1 and 945,120, it is not a prime number.