Made of platinum and worth $1 TRILLION each.

[Chex]

You can find it in subsection (k) of 31 USC 5112, which governs "Denominations, specifications, and design of coins."

(k) The Secretary may mint and issue platinum bullion coins and proof platinum coins in accordance with such specifications, designs, varieties, quantities, denominations, and inscriptions as the Secretary, in the Secretary's discretion, may prescribe from time to time.

Thanks to a law, the government can mint a platinum coin worth any amount.

It then can deposit it at the Federal Reserve to pay off $1 trillion in debt, which would swing the government far below its debt limit.

There are questions about whether this really would be legal or constitutional though.

It then can deposit it at the Federal Reserve to pay me off.