A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 7261500 can be evenly divided by 1 2 3 4 5 6 10 12 15 20 25 30 47 50 60 75 94 100 103 125 141 150 188 206 235 250 282 300 309 375 412 470 500 515 564 618 705 750 940 1,030 1,175 1,236 1,410 1,500 1,545 2,060 2,350 2,575 2,820 3,090 3,525 4,700 4,841 5,150 5,875 6,180 7,050 7,725 9,682 10,300 11,750 12,875 14,100 14,523 15,450 17,625 19,364 23,500 24,205 25,750 29,046 30,900 35,250 38,625 48,410 51,500 58,092 70,500 72,615 77,250 96,820 121,025 145,230 154,500 242,050 290,460 363,075 484,100 605,125 726,150 1,210,250 1,452,300 1,815,375 2,420,500 3,630,750 and 7,261,500, with no remainder.
Since 7,261,500 cannot be divided by just 1 and 7,261,500, it is not a prime number.