Question Number 117172 by zakirullah last updated on 10/Oct/20
Answered by $@y@m last updated on 10/Oct/20
$$\mathrm{21168}=\mathrm{2}×\mathrm{2}×\mathrm{2}×\mathrm{2}×\mathrm{3}×\mathrm{3}×\mathrm{3}×\mathrm{7}×\mathrm{7} \\ $$$$\mathrm{3}\:{has}\:{no}\:{pair}. \\ $$$$\therefore\:\mathrm{21168}\:{must}\:{be}\:{divided}\:{by}\:\mathrm{3} \\ $$$${to}\:{yield}\:{perfect}\:{square}. \\ $$