A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 2620200 can be evenly divided by 1 2 3 4 5 6 8 10 11 12 15 20 22 24 25 30 33 40 44 50 55 60 66 75 88 100 110 120 132 150 165 200 220 264 275 300 330 397 440 550 600 660 794 825 1,100 1,191 1,320 1,588 1,650 1,985 2,200 2,382 3,176 3,300 3,970 4,367 4,764 5,955 6,600 7,940 8,734 9,528 9,925 11,910 13,101 15,880 17,468 19,850 21,835 23,820 26,202 29,775 34,936 39,700 43,670 47,640 52,404 59,550 65,505 79,400 87,340 104,808 109,175 119,100 131,010 174,680 218,350 238,200 262,020 327,525 436,700 524,040 655,050 873,400 1,310,100 and 2,620,200, with no remainder.
Since 2,620,200 cannot be divided by just 1 and 2,620,200, it is not a prime number.