A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 4027520 can be evenly divided by 1 2 4 5 7 8 10 14 16 20 28 29 31 32 35 40 56 58 62 64 70 80 112 116 124 128 140 145 155 160 203 217 224 232 248 280 290 310 320 406 434 448 464 496 560 580 620 640 812 868 896 899 928 992 1,015 1,085 1,120 1,160 1,240 1,624 1,736 1,798 1,856 1,984 2,030 2,170 2,240 2,320 2,480 3,248 3,472 3,596 3,712 3,968 4,060 4,340 4,480 4,495 4,640 4,960 6,293 6,496 6,944 7,192 8,120 8,680 8,990 9,280 9,920 12,586 12,992 13,888 14,384 16,240 17,360 17,980 18,560 19,840 25,172 25,984 27,776 28,768 31,465 32,480 34,720 35,960 50,344 57,536 62,930 64,960 69,440 71,920 100,688 115,072 125,860 129,920 138,880 143,840 201,376 251,720 287,680 402,752 503,440 575,360 805,504 1,006,880 2,013,760 and 4,027,520, with no remainder.
Since 4,027,520 cannot be divided by just 1 and 4,027,520, it is not a prime number.