Ejim's point total was the most-ever for a Cyclone player in a conference game, beating the old mark of 47 set by Barry Stevens in 1985.
He also dominated the boards with 18 rebounds as Iowa State (18-4, 6-4 Big 12) cruised to an easy victory.
Georges Niang provided 11 points, six rebounds and six assists.
The Horned Frogs (9-13, 0-10) were led by Kyan Anderson with 27 points.
Karviar Shepherd added 11 points and eight rebounds.