A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 2354400 can be evenly divided by 1 2 3 4 5 6 8 9 10 12 15 16 18 20 24 25 27 30 32 36 40 45 48 50 54 60 72 75 80 90 96 100 108 109 120 135 144 150 160 180 200 216 218 225 240 270 288 300 327 360 400 432 436 450 480 540 545 600 654 675 720 800 864 872 900 981 1,080 1,090 1,200 1,308 1,350 1,440 1,635 1,744 1,800 1,962 2,160 2,180 2,400 2,616 2,700 2,725 2,943 3,270 3,488 3,600 3,924 4,320 4,360 4,905 5,232 5,400 5,450 5,886 6,540 7,200 7,848 8,175 8,720 9,810 10,464 10,800 10,900 11,772 13,080 14,715 15,696 16,350 17,440 19,620 21,600 21,800 23,544 24,525 26,160 29,430 31,392 32,700 39,240 43,600 47,088 49,050 52,320 58,860 65,400 73,575 78,480 87,200 94,176 98,100 117,720 130,800 147,150 156,960 196,200 235,440 261,600 294,300 392,400 470,880 588,600 784,800 1,177,200 and 2,354,400, with no remainder.
Since 2,354,400 cannot be divided by just 1 and 2,354,400, it is not a prime number.