A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 7793136 can be evenly divided by 1 2 3 4 6 8 9 12 13 16 18 23 24 26 36 39 46 48 52 69 72 78 92 104 117 138 144 156 181 184 207 208 234 276 299 312 362 368 414 468 543 552 598 624 724 828 897 936 1,086 1,104 1,196 1,448 1,629 1,656 1,794 1,872 2,172 2,353 2,392 2,691 2,896 3,258 3,312 3,588 4,163 4,344 4,706 4,784 5,382 6,516 7,059 7,176 8,326 8,688 9,412 10,764 12,489 13,032 14,118 14,352 16,652 18,824 21,177 21,528 24,978 26,064 28,236 33,304 37,467 37,648 42,354 43,056 49,956 54,119 56,472 66,608 74,934 84,708 99,912 108,238 112,944 149,868 162,357 169,416 199,824 216,476 299,736 324,714 338,832 432,952 487,071 599,472 649,428 865,904 974,142 1,298,856 1,948,284 2,597,712 3,896,568 and 7,793,136, with no remainder.
Since 7,793,136 cannot be divided by just 1 and 7,793,136, it is not a prime number.