A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 7501320 can be evenly divided by 1 2 3 4 5 6 8 9 10 12 15 18 20 24 30 36 40 45 60 67 72 90 120 134 180 201 268 311 335 360 402 536 603 622 670 804 933 1,005 1,206 1,244 1,340 1,555 1,608 1,866 2,010 2,412 2,488 2,680 2,799 3,015 3,110 3,732 4,020 4,665 4,824 5,598 6,030 6,220 7,464 8,040 9,330 11,196 12,060 12,440 13,995 18,660 20,837 22,392 24,120 27,990 37,320 41,674 55,980 62,511 83,348 104,185 111,960 125,022 166,696 187,533 208,370 250,044 312,555 375,066 416,740 500,088 625,110 750,132 833,480 937,665 1,250,220 1,500,264 1,875,330 2,500,440 3,750,660 and 7,501,320, with no remainder.
Since 7,501,320 cannot be divided by just 1 and 7,501,320, it is not a prime number.