Solving nⁿ=20880467999847912034355032910567 =========================================== Here's a nice equation: what is n if nⁿ=20880467999847912034355032910567 provided that n is an integer. How do we approach it? 1. Count the digits: 12345678901234567890123456789012 20880467999847912034355032910567 2. Find where the solution lies: The number of digits in 20880467999847912034355032910567 is 32. Thus, n cannot be a sinlge-digit number because 9⁹<10⁹ n has two digits. And 32=16 × 2 And because 100¹⁵=10³⁰, whose lenght is only 31, thus n>15 And the smallest two digit number is 10, and 10³² is of length 33, thus n<32 3. Elimination: n is an odd number whose unit digits cannot be 1,5 or 9. That leaves us with 17,23 and 27 The last two digits of nⁿ are 67, which means that nⁿ leaves a remainder of 3 when divided by 4, which means that: n ≡ 3 mod 4 which leves us with 23 and 27, but 27²⁷ ≡ 7³ mod 10 ≡ 3 mod 10 That leaves us with n = 23 our solution.