A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 292320 can be evenly divided by 1 2 3 4 5 6 7 8 9 10 12 14 15 16 18 20 21 24 28 29 30 32 35 36 40 42 45 48 56 58 60 63 70 72 80 84 87 90 96 105 112 116 120 126 140 144 145 160 168 174 180 203 210 224 232 240 252 261 280 288 290 315 336 348 360 406 420 435 464 480 504 522 560 580 609 630 672 696 720 812 840 870 928 1,008 1,015 1,044 1,120 1,160 1,218 1,260 1,305 1,392 1,440 1,624 1,680 1,740 1,827 2,016 2,030 2,088 2,320 2,436 2,520 2,610 2,784 3,045 3,248 3,360 3,480 3,654 4,060 4,176 4,640 4,872 5,040 5,220 6,090 6,496 6,960 7,308 8,120 8,352 9,135 9,744 10,080 10,440 12,180 13,920 14,616 16,240 18,270 19,488 20,880 24,360 29,232 32,480 36,540 41,760 48,720 58,464 73,080 97,440 146,160 and 292,320, with no remainder.
Since 292,320 cannot be divided by just 1 and 292,320, it is not a prime number.