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Carlo Beenakker
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Such an abundant number with abundance 1 is called a quasiperfect number. None have been found, according to Wikipedia. This 1982 article found that if a quasiperfect number exists, it must be an odd square number greater than $10^{35}$ and have at least seven distinct prime factors.

Carlo Beenakker
  • 188.2k
  • 18
  • 448
  • 651