9801/Mistake

Source Work

1986: David Wells: Curious and Interesting Numbers:

The Dictionary
$9801$


1997: David Wells: Curious and Interesting Numbers (2nd ed.):

The Dictionary
$9801$


Mistake

$9801 = 99^2$ and $98 + 01 = 99$, so $9801$ is a Kaprekar number.


Correction

By the usual definition, this makes $99$ a Kaprekar number, not $9801$.

The squares of Kaprekar numbers are not considered to be Kaprekar numbers unless they are Kaprekar in their own right.


Sources

  • 1986: David Wells: Curious and Interesting Numbers ... (previous) ... (next): $9801$
  • 1997: David Wells: Curious and Interesting Numbers (2nd ed.) ... (previous) ... (next): $9801$
This article is issued from ProofWiki. The text is available under Creative Commons Attribution-ShareAlike License unless otherwise noted. Additional terms may apply for the media files.