A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 483000 can be evenly divided by 1 2 3 4 5 6 7 8 10 12 14 15 20 21 23 24 25 28 30 35 40 42 46 50 56 60 69 70 75 84 92 100 105 115 120 125 138 140 150 161 168 175 184 200 210 230 250 276 280 300 322 345 350 375 420 460 483 500 525 552 575 600 644 690 700 750 805 840 875 920 966 1,000 1,050 1,150 1,288 1,380 1,400 1,500 1,610 1,725 1,750 1,932 2,100 2,300 2,415 2,625 2,760 2,875 3,000 3,220 3,450 3,500 3,864 4,025 4,200 4,600 4,830 5,250 5,750 6,440 6,900 7,000 8,050 8,625 9,660 10,500 11,500 12,075 13,800 16,100 17,250 19,320 20,125 21,000 23,000 24,150 32,200 34,500 40,250 48,300 60,375 69,000 80,500 96,600 120,750 161,000 241,500 and 483,000, with no remainder.
Since 483,000 cannot be divided by just 1 and 483,000, it is not a prime number.