Square whose Divisor Sum is Cubic

Theorem

The number $1 \, 857 \, 437 \, 604$ is a square number whose divisor sum is a cube.


Proof

\(\ds 1 \, 857 \, 437 \, 604\) \(=\) \(\ds 43 \, 098^2\)
\(\ds \map {\sigma_1} {1 \, 857 \, 437 \, 604}\) \(=\) \(\ds 5 \, 168 \, 743 \, 489\) $\sigma_1$ of $1 \, 857 \, 437 \, 604$
\(\ds \) \(=\) \(\ds 1729^3\)

$\blacksquare$


Sources

  • 1964: Albert H. Beiler: Recreations in the Theory of Numbers
  • 1986: David Wells: Curious and Interesting Numbers ... (previous) ... (next): $1,857,437,604$
  • 1997: David Wells: Curious and Interesting Numbers (2nd ed.) ... (previous) ... (next): $1,857,437,604$