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MathNet 2012 Question 28

Math Olympiad Vault · MathNet 2012

Question 28

For any positive integer $n$, let $a_1, a_2, \dots, a_m$ be all the positive divisors of $n$, where $m \ge 1$. If there exist $m$ integers $b_1, b_2, \dots, b_m$ such that $n = \sum_{i=1}^{m} (-1)^{b_i} a_i$, then we say that $n$ is a *good number*. Prove that there exists a good number with exactly 2013 distinct prime factors.