I assume you mean on June 6th, 1944?

In that case, no, the Germans had many more men than 500. Based either on the beaches or shortly behind them were the 21st Panzer Division, 352nd Infantry Division, 709th Static Division, and 716th Static Division. This accounts for roughly 50,000 men.

In addition to these were a number of nearby divisions. For example the 91st Infantry Division (formerly Air Landing Division similar to an American Airborne division) was on the Cotentin peninsula and was able to get to the assault area by midday and mixed it up with the 82nd and 101st American Airborne Divisions. So in addition to the 50,000 Germans immediately defending the assault area, there were another 20-30,000 who were close enough to see battle on June 6th.

Against this the Americans, British, and Canadians threw 10+ divisions accounting for about 150,000 men, plus naval and air support.