A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 3460380 can be evenly divided by 1 2 3 4 5 6 7 10 11 12 14 15 20 21 22 28 30 33 35 42 44 49 55 60 66 70 77 84 98 105 107 110 132 140 147 154 165 196 210 214 220 231 245 294 308 321 330 385 420 428 462 490 535 539 588 642 660 735 749 770 924 980 1,070 1,078 1,155 1,177 1,284 1,470 1,498 1,540 1,605 1,617 2,140 2,156 2,247 2,310 2,354 2,695 2,940 2,996 3,210 3,234 3,531 3,745 4,494 4,620 4,708 5,243 5,390 5,885 6,420 6,468 7,062 7,490 8,085 8,239 8,988 10,486 10,780 11,235 11,770 14,124 14,980 15,729 16,170 16,478 17,655 20,972 22,470 23,540 24,717 26,215 31,458 32,340 32,956 35,310 41,195 44,940 49,434 52,430 57,673 62,916 70,620 78,645 82,390 98,868 104,860 115,346 123,585 157,290 164,780 173,019 230,692 247,170 288,365 314,580 346,038 494,340 576,730 692,076 865,095 1,153,460 1,730,190 and 3,460,380, with no remainder.
Since 3,460,380 cannot be divided by just 1 and 3,460,380, it is not a prime number.