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2015 Advanced #10

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July 8, 2022
2015Advanced Topics Test

Problem Statement

Let σ(n)\sigma(n) be the sum of all the positive divisors of nn. Let aa be the smallest positive integer greater than or equal to 20152015 for which there exists some positive integer nn satisfying σ(n)=a\sigma(n)=a. Finally, let bb be the largest such value of nn. Compute a+ba+b.
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