Deceniums or Decenniums: How To spell?

The word Deceniums is misspelled against Decenniums, which is plural of "Decennium"

Decenniums has double "nn" is mispronounced as "n"
Remember double 'NN' in between the strings dece & iums which should not be misspelled with single 'N'
Wrong Spelling: dece-n-iums
Correct Spelling: dece-nn-iums
Check more misspelled words of Decenniums to spell it correct.