A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 604200 can be evenly divided by 1 2 3 4 5 6 8 10 12 15 19 20 24 25 30 38 40 50 53 57 60 75 76 95 100 106 114 120 150 152 159 190 200 212 228 265 285 300 318 380 424 456 475 530 570 600 636 760 795 950 1,007 1,060 1,140 1,272 1,325 1,425 1,590 1,900 2,014 2,120 2,280 2,650 2,850 3,021 3,180 3,800 3,975 4,028 5,035 5,300 5,700 6,042 6,360 7,950 8,056 10,070 10,600 11,400 12,084 15,105 15,900 20,140 24,168 25,175 30,210 31,800 40,280 50,350 60,420 75,525 100,700 120,840 151,050 201,400 302,100 and 604,200, with no remainder.
Since 604,200 cannot be divided by just 1 and 604,200, it is not a prime number.