The U.S. national debt hit $14.3 trillion, reaching its legal borrowing limit on Monday.

According to Timothy Geithner, the U.S. Treasury Secretary, the country borrows about $125 billion per month. This means $4 billion per day, $168 million per hour, or $40,000 per second.

The amount of debt will pressure the country into a default, which the Congress must raise the debt ceiling in order to avoid such happening. The White House is trying to find a way to cut federal spending and negotiate with lawmakers for a debt-limit increase.

At one point, President Ronald Reagan has famously said, “a trillion dollars would be a stack of $1,000 bills 67 miles high,” regarding the U.S. national debt in 1981. If you do the math, $14.3 trillion would be over 900 miles if you stack $1,000 bills.