A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 5340400 can be evenly divided by 1 2 4 5 8 10 13 16 20 25 26 40 50 52 65 79 80 100 104 130 158 169 200 208 260 316 325 338 395 400 520 632 650 676 790 845 1,027 1,040 1,264 1,300 1,352 1,580 1,690 1,975 2,054 2,600 2,704 3,160 3,380 3,950 4,108 4,225 5,135 5,200 6,320 6,760 7,900 8,216 8,450 10,270 13,351 13,520 15,800 16,432 16,900 20,540 25,675 26,702 31,600 33,800 41,080 51,350 53,404 66,755 67,600 82,160 102,700 106,808 133,510 205,400 213,616 267,020 333,775 410,800 534,040 667,550 1,068,080 1,335,100 2,670,200 and 5,340,400, with no remainder.
Since 5,340,400 cannot be divided by just 1 and 5,340,400, it is not a prime number.