A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 3765330 can be evenly divided by 1 2 3 5 6 9 10 15 17 18 23 30 34 45 46 51 69 85 90 102 107 115 138 153 170 207 214 230 255 306 321 345 391 414 510 535 642 690 765 782 963 1,035 1,070 1,173 1,530 1,605 1,819 1,926 1,955 2,070 2,346 2,461 3,210 3,519 3,638 3,910 4,815 4,922 5,457 5,865 7,038 7,383 9,095 9,630 10,914 11,730 12,305 14,766 16,371 17,595 18,190 22,149 24,610 27,285 32,742 35,190 36,915 41,837 44,298 54,570 73,830 81,855 83,674 110,745 125,511 163,710 209,185 221,490 251,022 376,533 418,370 627,555 753,066 1,255,110 1,882,665 and 3,765,330, with no remainder.
Since 3,765,330 cannot be divided by just 1 and 3,765,330, it is not a prime number.