A staggering number is one that's extremely high or surprising.
You might hear someone say "The new record for most hours worked without sleep is staggering - 264 hours!" when they mean to emphasize how incredible that amount of time is. This word is often used to describe statistics, numbers, or amounts that are unusually large. It can also be used to express shock or amazement at something. For example, "The price of the new iPhone is staggering" would suggest that it's much more expensive than anyone expected. In general, when we call a number staggering, we're highlighting its enormity and expressing our reaction to it.
Sway unsteadily, reel, or totter.
The motion of one who staggers.
Incredible, overwhelming, amazing.
Example: The army suffered a staggering defeat.
