The U.S. IOU recently hit $10 trillion, a 14-digit number. The clock near Times Square has 13 digits plus one for the dollar sign, creating a quandary about how to express the debt, the Chicago Tribune reported.

Debt minders at The Durst Organization turned the digital dollar sign into a "1" and had a dollar-sign sticker mounted as a temporary measure.

"Seymour Durst was a visionary. He began thinking and writing about the national debt long before most people," said Jordan Barowitz, spokesman for the real estate firm.

Durst, who died in 1995, erected the sign in 1989, when the national debt was a mere $2.7 trillion.

The company plans a more permanent replacement next year that could be more telling, the Tribune reported.

"We'd like to do something more flexible and dynamic, that can be programmed to show the debt in different ways," said Barowitz. "It has family share now, but we'd like to introduce different variables into it."