A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 4001550 can be evenly divided by 1 2 3 5 6 7 10 14 15 21 25 30 35 37 42 50 70 74 75 103 105 111 150 175 185 206 210 222 259 309 350 370 515 518 525 555 618 721 777 925 1,030 1,050 1,110 1,295 1,442 1,545 1,554 1,850 2,163 2,575 2,590 2,775 3,090 3,605 3,811 3,885 4,326 5,150 5,550 6,475 7,210 7,622 7,725 7,770 10,815 11,433 12,950 15,450 18,025 19,055 19,425 21,630 22,866 26,677 36,050 38,110 38,850 53,354 54,075 57,165 80,031 95,275 108,150 114,330 133,385 160,062 190,550 266,770 285,825 400,155 571,650 666,925 800,310 1,333,850 2,000,775 and 4,001,550, with no remainder.
Since 4,001,550 cannot be divided by just 1 and 4,001,550, it is not a prime number.