A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 2576700 can be evenly divided by 1 2 3 4 5 6 7 9 10 12 14 15 18 20 21 25 28 30 35 36 42 45 50 60 63 70 75 84 90 100 105 126 140 150 175 180 210 225 252 300 315 350 409 420 450 525 630 700 818 900 1,050 1,227 1,260 1,575 1,636 2,045 2,100 2,454 2,863 3,150 3,681 4,090 4,908 5,726 6,135 6,300 7,362 8,180 8,589 10,225 11,452 12,270 14,315 14,724 17,178 18,405 20,450 24,540 25,767 28,630 30,675 34,356 36,810 40,900 42,945 51,534 57,260 61,350 71,575 73,620 85,890 92,025 103,068 122,700 128,835 143,150 171,780 184,050 214,725 257,670 286,300 368,100 429,450 515,340 644,175 858,900 1,288,350 and 2,576,700, with no remainder.
Since 2,576,700 cannot be divided by just 1 and 2,576,700, it is not a prime number.