1,157,920,892,373,161,954,235,709,850,086,879,078,532,699,846,656,405,640,394,57
I have created the software structure to realize this
Considering that you're unable to place the commas correctly in a large number, and that you truncated the number, your software would be unlikely to be either useful or reliable
If it's supposed to be 2^256 ...
115,792,089,237,316,195,423,570,985,008,687,907,853,269,984,665,640,564,039,457,584,007,913,129,639,936