A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 3356730 can be evenly divided by 1 2 3 5 6 9 10 13 15 18 19 26 30 38 39 45 57 65 78 90 95 114 117 130 151 171 190 195 234 247 285 302 342 390 453 494 570 585 741 755 855 906 1,170 1,235 1,359 1,482 1,510 1,710 1,963 2,223 2,265 2,470 2,718 2,869 3,705 3,926 4,446 4,530 5,738 5,889 6,795 7,410 8,607 9,815 11,115 11,778 13,590 14,345 17,214 17,667 19,630 22,230 25,821 28,690 29,445 35,334 37,297 43,035 51,642 58,890 74,594 86,070 88,335 111,891 129,105 176,670 186,485 223,782 258,210 335,673 372,970 559,455 671,346 1,118,910 1,678,365 and 3,356,730, with no remainder.
Since 3,356,730 cannot be divided by just 1 and 3,356,730, it is not a prime number.