A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 2000376 can be evenly divided by 1 2 3 4 6 7 8 9 12 14 18 21 24 27 28 36 42 49 54 56 63 72 81 84 98 108 126 147 162 168 189 196 216 243 252 294 324 343 378 392 441 486 504 567 588 648 686 729 756 882 972 1,029 1,134 1,176 1,323 1,372 1,458 1,512 1,701 1,764 1,944 2,058 2,268 2,646 2,744 2,916 3,087 3,402 3,528 3,969 4,116 4,536 5,103 5,292 5,832 6,174 6,804 7,938 8,232 9,261 10,206 10,584 11,907 12,348 13,608 15,876 18,522 20,412 23,814 24,696 27,783 31,752 35,721 37,044 40,824 47,628 55,566 71,442 74,088 83,349 95,256 111,132 142,884 166,698 222,264 250,047 285,768 333,396 500,094 666,792 1,000,188 and 2,000,376, with no remainder.
Since 2,000,376 cannot be divided by just 1 and 2,000,376, it is not a prime number.