These are not palindromes but still useless but interesting

 

12²   =   144

reverse the digits

21²   =  441

 

and

 

13²   =  169

reverse the digits

31²   =   961

Nice.

Although it's not that useless...

32 minutes ago, joigus said:

Although it's not that useless...

Oh  ??

7 minutes ago, studiot said:

Oh  ??

Calculation shortcuts and mnemonics.

2 minutes ago, joigus said:

Calculation shortcuts and mnemonics.

Thank you I will (try to) remember that next time I want 13 squared or 12 squared.

They are 31 squared and 21 squared reversed.

+1

Edited September 9, 20205 yr by studiot

On 9/2/2020 at 5:58 PM, Airbrush said:

Salvador Dali was famous for saying "I know what I eat, but I don't know what I do."

Another Dali factoid: He doodled on the cheques so they would never be cashed:

https://theuijunkie.com/salvador-dali-cheque-restaurants/

Hello! Here are some useless facts for you: rubber bands that are refrigerated last longer, playing dance music can help ward off mosquitoes, and peanuts are one of the ingredients of dynamite!

Provided by myself from (url deleted; violation of rule 2.7)