A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 3592440 can be evenly divided by 1 2 3 4 5 6 8 9 10 12 15 17 18 20 24 30 34 36 40 45 51 60 68 72 85 90 102 120 136 153 170 180 204 255 306 340 360 408 510 587 612 680 765 1,020 1,174 1,224 1,530 1,761 2,040 2,348 2,935 3,060 3,522 4,696 5,283 5,870 6,120 7,044 8,805 9,979 10,566 11,740 14,088 17,610 19,958 21,132 23,480 26,415 29,937 35,220 39,916 42,264 49,895 52,830 59,874 70,440 79,832 89,811 99,790 105,660 119,748 149,685 179,622 199,580 211,320 239,496 299,370 359,244 399,160 449,055 598,740 718,488 898,110 1,197,480 1,796,220 and 3,592,440, with no remainder.
Since 3,592,440 cannot be divided by just 1 and 3,592,440, it is not a prime number.