When the same four-digit number is subtracted from the three numbers 1983, 1993, and 2003, the difference obtained is three prime numbers. What is the four-digit number?
1983、1993、2003这三个数分别减去同一个四位数时，得到的差是三个质数，这个四位数是多少．
<gadget id="calculator">1_983 - 3</gadget>
<output>1_980</output>

<result>1_980</result>