A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 5149536 can be evenly divided by 1 2 3 4 6 7 8 12 14 16 21 24 28 32 42 48 56 79 84 96 97 112 158 168 194 224 237 291 316 336 388 474 553 582 632 672 679 776 948 1,106 1,164 1,264 1,358 1,552 1,659 1,896 2,037 2,212 2,328 2,528 2,716 3,104 3,318 3,792 4,074 4,424 4,656 5,432 6,636 7,584 7,663 8,148 8,848 9,312 10,864 13,272 15,326 16,296 17,696 21,728 22,989 26,544 30,652 32,592 45,978 53,088 53,641 61,304 65,184 91,956 107,282 122,608 160,923 183,912 214,564 245,216 321,846 367,824 429,128 643,692 735,648 858,256 1,287,384 1,716,512 2,574,768 and 5,149,536, with no remainder.
Since 5,149,536 cannot be divided by just 1 and 5,149,536, it is not a prime number.