A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 7600600 can be evenly divided by 1 2 4 5 7 8 10 14 20 25 28 35 40 50 56 61 70 89 100 122 140 175 178 200 244 280 305 350 356 427 445 488 610 623 700 712 854 890 1,220 1,246 1,400 1,525 1,708 1,780 2,135 2,225 2,440 2,492 3,050 3,115 3,416 3,560 4,270 4,450 4,984 5,429 6,100 6,230 8,540 8,900 10,675 10,858 12,200 12,460 15,575 17,080 17,800 21,350 21,716 24,920 27,145 31,150 38,003 42,700 43,432 54,290 62,300 76,006 85,400 108,580 124,600 135,725 152,012 190,015 217,160 271,450 304,024 380,030 542,900 760,060 950,075 1,085,800 1,520,120 1,900,150 3,800,300 and 7,600,600, with no remainder.
Since 7,600,600 cannot be divided by just 1 and 7,600,600, it is not a prime number.