Clay Harden borrowed $21,000 from a bank at an interest rate of 8% compounded monthly. The loan will be repaid in 36 equal monthly installments over three years. Immediately after his 19th payment, Clay desires to pay the remainder of the loan in a single payment. Compute the total amount he must pay. The total amount Clay must pay immediately after his 19th payment will be $. (Round to the nearest dollar.)