【How-to】What is the largest unsigned n bit binary number

The maximum value of an unsigned 256-bit integer is 2²⁵⁶ − 1, written in decimal as 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,​935 or approximately as 1.1579 x 10⁷⁷.