Needs["NumberTheory`EgyptianDecomposition`"]

EgyptianDecomposition[1/4]

EgyptianDecomposition[2/3]

EgyptianDecomposition[19/20]

1/2+1/3+1/9+1/180

EgyptianDecomposition[Sum[1/i,{i,1,1000}]]

EgyptianDecomposition[NSum[1/i,{i,1,1000}]]