A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 1471320 can be evenly divided by 1 2 3 4 5 6 8 9 10 12 15 18 20 24 30 36 40 45 60 61 67 72 90 120 122 134 180 183 201 244 268 305 335 360 366 402 488 536 549 603 610 670 732 804 915 1,005 1,098 1,206 1,220 1,340 1,464 1,608 1,830 2,010 2,196 2,412 2,440 2,680 2,745 3,015 3,660 4,020 4,087 4,392 4,824 5,490 6,030 7,320 8,040 8,174 10,980 12,060 12,261 16,348 20,435 21,960 24,120 24,522 32,696 36,783 40,870 49,044 61,305 73,566 81,740 98,088 122,610 147,132 163,480 183,915 245,220 294,264 367,830 490,440 735,660 and 1,471,320, with no remainder.
Since 1,471,320 cannot be divided by just 1 and 1,471,320, it is not a prime number.