A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 4098072 can be evenly divided by 1 2 3 4 6 8 11 12 19 22 24 33 38 43 44 57 66 76 86 88 114 129 132 152 172 209 228 258 264 344 361 418 456 473 516 627 722 817 836 946 1,032 1,083 1,254 1,419 1,444 1,634 1,672 1,892 2,166 2,451 2,508 2,838 2,888 3,268 3,784 3,971 4,332 4,902 5,016 5,676 6,536 7,942 8,664 8,987 9,804 11,352 11,913 15,523 15,884 17,974 19,608 23,826 26,961 31,046 31,768 35,948 46,569 47,652 53,922 62,092 71,896 93,138 95,304 107,844 124,184 170,753 186,276 215,688 341,506 372,552 512,259 683,012 1,024,518 1,366,024 2,049,036 and 4,098,072, with no remainder.
Since 4,098,072 cannot be divided by just 1 and 4,098,072, it is not a prime number.