There is no Champion spark plug with the part number 696798. There is a Briggs and Stratton part number 696798 that does cross reference with a Champion RJ 19LM.
You can cross reference a RC12PYP3 or RC12YC non-platinum spark plug for a Briggs 696798. The Briggs Platinum 696798 spark plug is for a snow blower. Part number 696020 for a Platinum plug from Sears is an equivalent also.
Most all brand spark plug brands are on the cross reference including Champion. Some of the brands that cross reference to Champion are Autolite and Denso,
8902 cross reference plug
rc12pyp3 or rc12yc non platnum plug
Rj19lm
Champion J19LM
Champion N12YC
Autolite 217.
Rn11yca
Cj8y
308
RC12YC in Champion