The number 1,594,404 can be evenly divided by 1 2 3 4 6 7 9 12 14 18 19 21 27 28 36 37 38 42 54 57 63 74 76 81 84 108 111 114 126 133 148 162 171 189 222 228 252 259 266 324 333 342 378 399 444 513 518 532 567 666 684 703 756 777 798 999 1,026 1,036 1,134 1,197 1,332 1,406 1,539 1,554 1,596 1,998 2,052 2,109 2,268 2,331 2,394 2,812 2,997 3,078 3,108 3,591 3,996 4,218 4,662 4,788 4,921 5,994 6,156 6,327 6,993 7,182 8,436 9,324 9,842 10,773 11,988 12,654 13,986 14,364 14,763 18,981 19,684 20,979 21,546 25,308 27,972 29,526 37,962 41,958 43,092 44,289 56,943 59,052 75,924 83,916 88,578 113,886 132,867 177,156 227,772 265,734 398,601 531,468 797,202 and 1,594,404, with no remainder.
Since 1,594,404 cannot be divided by just 1 and 1,594,404, it is a composite number.