53. A prize fund is divided into first, second, and third prizes. The prize for each first prize is 3 times that of each second prize, and the prize for each second prize is 3 times that of each third prize. The total prize fund is 10800 yuan. If the total prize money for the third prize is more than that for the second prize, and the total prize money for the second prize is more than that for the first prize, and the number of winners does not exceed 20, then the minimum prize money for the first prize is yuan. $\qquad$
Reference answer: 2700