A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 7636160 can be evenly divided by 1 2 4 5 7 8 10 14 16 20 28 32 35 40 49 56 64 70 80 98 112 140 160 196 224 245 280 320 392 448 487 490 560 784 974 980 1,120 1,568 1,948 1,960 2,240 2,435 3,136 3,409 3,896 3,920 4,870 6,818 7,792 7,840 9,740 13,636 15,584 15,680 17,045 19,480 23,863 27,272 31,168 34,090 38,960 47,726 54,544 68,180 77,920 95,452 109,088 119,315 136,360 155,840 190,904 218,176 238,630 272,720 381,808 477,260 545,440 763,616 954,520 1,090,880 1,527,232 1,909,040 3,818,080 and 7,636,160, with no remainder.
Since 7,636,160 cannot be divided by just 1 and 7,636,160, it is not a prime number.