Problem 211

Divisor Square Sum

For a positive integer `n`, let σ_{2}(`n`) be the sum of the squares of its divisors. For example,

σ_{2}(10) = 1 + 4 + 25 + 100 = 130.

Find the sum of all `n`, 0 `n` 64,000,000 such that σ_{2}(`n`) is a perfect square.

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