The most balanced factorization

MediumBrainteasers~9m

Write 1234567890=ab1234567890 = a \cdot b with positive integers a,ba, b. Among all such factorizations, let (a,b)(a^*, b^*) be the one minimizing ab|a - b| (the most balanced). Find a+ba^* + b^*.

Show hints (2)+
  1. Balanced factors straddle N35136\sqrt{N}\approx 35136. Factor N=232536073803N=2\cdot3^2\cdot5\cdot3607\cdot3803.
  2. 93803=342279\cdot3803=34227 and 253607=360702\cdot5\cdot3607=36070 are the closest pair.

Answer

Reveal answer →

70297

Want the full step-by-step worked solution? It's part of Premium - along with a worked solution for every question in the bank.

Asked at: Jane Street, SIG

Related questions