Here’s a PL/SQL program to find the reverse of a number:

```
DECLARE
num NUMBER;
reverse_num NUMBER := 0;
remainder NUMBER;
BEGIN
-- Prompt the user for input
num := #
-- Store the original number in a temporary variable
DECLARE
original_num NUMBER := num;
BEGIN
-- Calculate the reverse of the number
WHILE num > 0 LOOP
remainder := num MOD 10;
reverse_num := reverse_num * 10 + remainder;
num := FLOOR(num / 10);
END LOOP;
END;
-- Display the reverse of the number
DBMS_OUTPUT.PUT_LINE('The reverse of ' || original_num || ' is: ' || reverse_num);
END;
/
```

Explanation:

`DECLARE`

: This keyword indicates the start of the declaration section where we define variables.`num NUMBER;`

: This line declares a variable named`num`

of the NUMBER data type, which will store the original number.`reverse_num NUMBER := 0;`

: This line initializes the variable`reverse_num`

to 0. It will store the reverse of the original number.`remainder NUMBER;`

: This line declares a variable named`remainder`

of the NUMBER data type. It will store the remainder when dividing the number by 10.`BEGIN`

: This keyword signifies the beginning of the executable section.`num := #`

: This line prompts the user to enter the number and assigns the input value to the`num`

variable. The`&`

symbol is used to retrieve the value entered by the user.`DECLARE`

: This keyword indicates the start of the nested block where we define another variable to store the original number.`original_num NUMBER := num;`

: This line declares a variable named`original_num`

of the NUMBER data type and assigns it the value of`num`

. This variable will store the original number for display purposes.`BEGIN`

: This keyword signifies the beginning of the nested block’s executable section.`WHILE num > 0 LOOP`

: This loop will execute as long as the value of`num`

is greater than 0.`remainder := num MOD 10;`

: This line calculates the remainder when`num`

is divided by 10 and assigns it to the`remainder`

variable.`reverse_num := reverse_num * 10 + remainder;`

: This line updates the`reverse_num`

variable by multiplying it by 10 and adding the value of`remainder`

. This effectively builds the reverse of the number.`num := FLOOR(num / 10);`

: This line updates the value of`num`

by dividing it by 10 and taking the floor of the result. This effectively removes the rightmost digit from`num`

in each iteration.`END LOOP;`

: This statement marks the end of the loop.`DBMS_OUTPUT.PUT_LINE('The reverse of ' || original_num || ' is: ' || reverse_num);`

: This line uses the`DBMS_OUTPUT.PUT_LINE`

procedure to display the reverse of the original number. It concatenates the values of`original_num`

and`reverse_num`

to form a descriptive message.

By running this PL/SQL program, you can find the reverse of a given number. The program prompts the user to enter the number, calculates the reverse of the number using a loop, and then displays the reverse on the console. This allows you to quickly obtain the reverse of the given number.