If you know that the cube root of this number is an integer.

1、 1000 & lt； 593 19 & lt； 1000000, so the cube root is between 10 and 100, which is a double digit.

2. The unit is completely determined by the unit of the cube root. If the unit is calculated from 1 to 9, only the unit of 9 is 9, so the unit is 9.

3. Here is the ten digits, because the cube of 10 is 1000, so more than one thousand digits are completely determined by the ten digits. When the digit is set to 0, it is followed by 000, so you can safely remove the last three digits. Similar to the first step, draw an interval. If the cube of a number greater than 30 is less than 40, then the decimal number is 3.

So it's 39