A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 2358000 can be evenly divided by 1 2 3 4 5 6 8 9 10 12 15 16 18 20 24 25 30 36 40 45 48 50 60 72 75 80 90 100 120 125 131 144 150 180 200 225 240 250 262 300 360 375 393 400 450 500 524 600 655 720 750 786 900 1,000 1,048 1,125 1,179 1,200 1,310 1,500 1,572 1,800 1,965 2,000 2,096 2,250 2,358 2,620 3,000 3,144 3,275 3,600 3,930 4,500 4,716 5,240 5,895 6,000 6,288 6,550 7,860 9,000 9,432 9,825 10,480 11,790 13,100 15,720 16,375 18,000 18,864 19,650 23,580 26,200 29,475 31,440 32,750 39,300 47,160 49,125 52,400 58,950 65,500 78,600 94,320 98,250 117,900 131,000 147,375 157,200 196,500 235,800 262,000 294,750 393,000 471,600 589,500 786,000 1,179,000 and 2,358,000, with no remainder.
Since 2,358,000 cannot be divided by just 1 and 2,358,000, it is not a prime number.