The loan is 820,000, and the early repayment is 100,000, which can be shortened by 2 years.

A loan of 820,000 yuan. If the loan term is 20 years, the borrowing interest rate is 4.9, the repayment method is equal amounts of principal, and the monthly repayment amount is 4,461 yuan. If you repay 100,000 yuan in advance, the loan period can be shortened by about 2 years, and the final repayment period is about 18 years, and the monthly repayment amount will be reduced by nearly 500 yuan.

Early repayment of 100,000 yuan can shorten the repayment period of the loan, but the specific number of shortened years needs to be comprehensively considered based on factors such as the loan's term, interest rate, and repayment method.