A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 2341440 can be evenly divided by 1 2 3 4 5 6 8 9 10 12 15 16 18 20 24 27 30 32 36 40 45 48 54 60 64 72 80 90 96 108 120 135 144 160 180 192 216 240 270 271 288 320 360 432 480 540 542 576 720 813 864 960 1,080 1,084 1,355 1,440 1,626 1,728 2,160 2,168 2,439 2,710 2,880 3,252 4,065 4,320 4,336 4,878 5,420 6,504 7,317 8,130 8,640 8,672 9,756 10,840 12,195 13,008 14,634 16,260 17,344 19,512 21,680 24,390 26,016 29,268 32,520 36,585 39,024 43,360 48,780 52,032 58,536 65,040 73,170 78,048 86,720 97,560 117,072 130,080 146,340 156,096 195,120 234,144 260,160 292,680 390,240 468,288 585,360 780,480 1,170,720 and 2,341,440, with no remainder.
Since 2,341,440 cannot be divided by just 1 and 2,341,440, it is not a prime number.