The first step is to understand what it means when a number has an exponent. The “power” of a number indicates how many times the base would be multiplied by itself to reach the correct value.
The second step is to write the number in the base-exponent form, and lastly calculate what the final result would be. Consider the example of 2 to the power of 4: in exponent form that would be
So re-applying these steps to our particular problem, we first convert our word problem to a base-exponent form of:
To simplify this, all that is needed is to multiply it out:
21 x 21 x 21 x 21 x ... (for a total of 91 times) = 2098726376889212868660355885811966828020438449676320176711858938846542527395289316151812243748880470758800057447538319821
Therefore, 21 to the power of 91 is 2098726376889212868660355885811966828020438449676320176711858938846542527395289316151812243748880470758800057447538319821.