3224.9 yuan. The borrower applied for a provident fund loan of 670,000 yuan, the repayment period was 30 years, and the annual interest rate of the loan was 3.25%, so the monthly payment of 670,000 yuan was 3,224.9 yuan.

It should be noted that the above is only a theoretical calculation method, and there are many factors that can affect the change of loan interest and monthly payment. Including the repayment method, it will also affect the monthly payment. Under other conditions, the monthly payment of equal principal and interest is the same, while the monthly payment of average capital is the largest in the first month and decreases month by month, and the total interest of equal principal and interest is greater than that of average capital.