A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 1444320 can be evenly divided by 1 2 3 4 5 6 8 9 10 12 15 16 17 18 20 24 30 32 34 36 40 45 48 51 59 60 68 72 80 85 90 96 102 118 120 136 144 153 160 170 177 180 204 236 240 255 272 288 295 306 340 354 360 408 472 480 510 531 544 590 612 680 708 720 765 816 885 944 1,003 1,020 1,062 1,180 1,224 1,360 1,416 1,440 1,530 1,632 1,770 1,888 2,006 2,040 2,124 2,360 2,448 2,655 2,720 2,832 3,009 3,060 3,540 4,012 4,080 4,248 4,720 4,896 5,015 5,310 5,664 6,018 6,120 7,080 8,024 8,160 8,496 9,027 9,440 10,030 10,620 12,036 12,240 14,160 15,045 16,048 16,992 18,054 20,060 21,240 24,072 24,480 28,320 30,090 32,096 36,108 40,120 42,480 45,135 48,144 60,180 72,216 80,240 84,960 90,270 96,288 120,360 144,432 160,480 180,540 240,720 288,864 361,080 481,440 722,160 and 1,444,320, with no remainder.
Since 1,444,320 cannot be divided by just 1 and 1,444,320, it is not a prime number.