Oracle 18c

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CREATE TABLE tab( id INT GENERATED ALWAYS AS IDENTITY PRIMARY KEY, col CLOB )
BEGIN
 INSERT INTO tab(col) VALUES('123 4567 890 111 2222.3333/4444');
 INSERT INTO tab(col) VALUES('any characters 000 11111.,-2222@#$3333!?4444# any @#$ characters!?');
 INSERT INTO tab(col) VALUES('6Invoice #1 , 0 . 0 for the amount $1 2 ,* 3 has been processed!');
 INSERT INTO tab(col) VALUES(' 6Invoice #1 , 0 . 0 for the amount $1 2 ,* 3 has been processed!'); 
 INSERT INTO tab(col) VALUES('#1 , 0 . 0 for the amount $1 2 ,* 3 has been processed! '); 
 INSERT INTO tab(col) VALUES('#1 , 0 . 0 for the amount $1 2 ,* 3 has been processed!7');
END;
/
1 rows affected

SELECT ID, REGEXP_REPLACE(col,'[^0-9]') AS new_col
  FROM tab


ID
NEW_COL


1
1234567890111222233334444

2
00011111222233334444

3
6100123

4
6100123

5
100123

6
1001237


SELECT ID, REGEXP_REPLACE(col,'[^[:digit:]]') AS new_col
  FROM tab


ID
NEW_COL


1
1234567890111222233334444

2
00011111222233334444

3
6100123

4
6100123

5
100123

6
1001237


SELECT ID,
       col,       
       CASE
         WHEN REGEXP_INSTR(col, '[[:digit:]]') != 1 THEN
          REPLACE(REGEXP_SUBSTR(col, '[^[:digit:][:punct:]]+'), ' ')
       END || 
       REGEXP_REPLACE(col, '[^0-9]*([0-9]+|$)', '\1') ||
       REGEXP_SUBSTR(REGEXP_REPLACE(col, '[[:punct:] ]'), '[^[:digit:]]+$') AS new_col
  FROM tab


ID
COL
NEW_COL


1
123 4567 890 111 2222.3333/4444
1234567890111222233334444

2
any characters 000 11111.,-2222@#$3333!?4444# any @#$ characters!?
anycharacters00011111222233334444anycharacters

3
6Invoice #1 , 0 . 0 for the amount $1 2 ,* 3 has been processed!
6100123hasbeenprocessed

4
 6Invoice #1 , 0 . 0 for the amount $1 2 ,* 3 has been processed!
6100123hasbeenprocessed

5
#1 , 0 . 0 for the amount $1 2 ,* 3 has been processed!
100123hasbeenprocessed

6
#1 , 0 . 0 for the amount $1 2 ,* 3 has been processed!7
1001237

ID	NEW_COL
1	1234567890111222233334444
2	00011111222233334444
3	6100123
4	6100123
5	100123
6	1001237

ID	COL	NEW_COL
1	123 4567 890 111 2222.3333/4444	1234567890111222233334444
2	any characters 000 11111.,-2222@#$3333!?4444# any @#$ characters!?	anycharacters00011111222233334444anycharacters
3	6Invoice #1 , 0 . 0 for the amount $1 2 ,* 3 has been processed!	6100123hasbeenprocessed
4	6Invoice #1 , 0 . 0 for the amount $1 2 ,* 3 has been processed!	6100123hasbeenprocessed
5	#1 , 0 . 0 for the amount $1 2 ,* 3 has been processed!	100123hasbeenprocessed
6	#1 , 0 . 0 for the amount $1 2 ,* 3 has been processed!7	1001237