A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 3925530 can be evenly divided by 1 2 3 5 6 7 9 10 14 15 18 21 27 30 31 35 42 45 54 62 63 67 70 90 93 105 126 134 135 155 186 189 201 210 217 270 279 310 315 335 378 402 434 465 469 558 603 630 651 670 837 930 938 945 1,005 1,085 1,206 1,302 1,395 1,407 1,674 1,809 1,890 1,953 2,010 2,077 2,170 2,345 2,790 2,814 3,015 3,255 3,618 3,906 4,154 4,185 4,221 4,690 5,859 6,030 6,231 6,510 7,035 8,370 8,442 9,045 9,765 10,385 11,718 12,462 12,663 14,070 14,539 18,090 18,693 19,530 20,770 21,105 25,326 29,078 29,295 31,155 37,386 42,210 43,617 56,079 58,590 62,310 63,315 72,695 87,234 93,465 112,158 126,630 130,851 145,390 186,930 218,085 261,702 280,395 392,553 436,170 560,790 654,255 785,106 1,308,510 1,962,765 and 3,925,530, with no remainder.
Since 3,925,530 cannot be divided by just 1 and 3,925,530, it is not a prime number.