A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 3570138 can be evenly divided by 1 2 3 6 9 11 13 18 19 22 26 33 38 39 57 66 73 78 99 114 117 143 146 171 198 209 219 234 247 286 342 418 429 438 494 627 657 741 803 858 949 1,254 1,287 1,314 1,387 1,482 1,606 1,881 1,898 2,223 2,409 2,574 2,717 2,774 2,847 3,762 4,161 4,446 4,818 5,434 5,694 7,227 8,151 8,322 8,541 10,439 12,483 14,454 15,257 16,302 17,082 18,031 20,878 24,453 24,966 30,514 31,317 36,062 45,771 48,906 54,093 62,634 91,542 93,951 108,186 137,313 162,279 187,902 198,341 274,626 324,558 396,682 595,023 1,190,046 1,785,069 and 3,570,138, with no remainder.
Since 3,570,138 cannot be divided by just 1 and 3,570,138, it is not a prime number.