how do I show 12 numbers from a huge number?

[SheeppOSU]

The expression "2^2^34", or "2**2**34" in Python, could be written as 2(2 * 2 * 2 * 2...). The program can't do this because it doesn't have enough space. I haven't tried this yet, but you could try doing it the way a person would do it on paper. It would be a bit complicated to explain, so I'll do an example.
2426
x_53
['7', '2', '7', '8']
['1', '2', '1', '3', '0', '0']
Then the code should line them up and add like this

list1 = ['7', '2', '7', '8']
list2 = ['1', '2', '1', '3', '0', '0']
stringAnswer = ''
for x in range(0, len(list2)) + 1):
    if x < len(list2) - len(list1):
        stringAnswer += list2[x]
    else:
        stringAnswer += str(int(list2[x + (len(list2) - len(list1))]) + int(list1[x]))

I didn't test it so idk if my example code here will work properly, but I hope you get the idea of what I'm trying to do.
EDIT: The code on line 8, could possibly output a 2 digit number, and I didn't work that out, also, the code above would be adding backwards as well as adding the number to stringAnswer backwards. There are a few problems with the code, but again, it's just to give the idea of what can be done.