Weird Number in Two's Complement
The binary number 100..0002 is called a weird number because after inverting and adding 1 (taking the two's complement) it does not change.
100..000 inverting
011..111
+ 1
------------
100..000
This number (100..002 = -2N-1) is the most negative of two's complement numbers. And it has no positive counterpart.
Harris D. M., Harris S. L. - Digital Design and Computer Architecture, 2nd Edition - 2012
1.4.6 Signed Binary Numbers - 15 page