A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 5600868 can be evenly divided by 1 2 3 4 6 7 12 13 14 21 23 26 28 39 42 46 52 69 78 84 91 92 138 156 161 182 223 273 276 299 322 364 446 483 546 598 644 669 892 897 966 1,092 1,196 1,338 1,561 1,794 1,932 2,093 2,676 2,899 3,122 3,588 4,186 4,683 5,129 5,798 6,244 6,279 8,372 8,697 9,366 10,258 11,596 12,558 15,387 17,394 18,732 20,293 20,516 25,116 30,774 34,788 35,903 40,586 60,879 61,548 66,677 71,806 81,172 107,709 121,758 133,354 143,612 200,031 215,418 243,516 266,708 400,062 430,836 466,739 800,124 933,478 1,400,217 1,866,956 2,800,434 and 5,600,868, with no remainder.
Since 5,600,868 cannot be divided by just 1 and 5,600,868, it is not a prime number.