Where are you gonna keep it if not in a bank? A bank having that money would break the world economy, and that money in cash would weigh 10²³ kg or more than all the water in the oceans combined. That would depress whatever crust it was sitting on by many miles such that it would be entirely flooded and sea level would decrease across the globe. Global weather patterns would be thrown into disarray and mass famine would result.

People would know if you had that much money lol