Oracle 18c

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CREATE TABLE long_numbers ( value ) AS
SELECT '1123123211231231231231231231231231231123123123123123123123213213123213123213123123213123123123123213123123123126666666355555899' FROM DUAL UNION ALL
SELECT '112312321123123123123123123123123123112312312312312312312321321312321312321312312321312312312312321312312312312666666635555589' FROM DUAL UNION ALL
SELECT '0.000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000012345678901234567890123456789012345678901234567890' FROM DUAL;
3 rows affected

SELECT TO_NUMBER( value DEFAULT NULL ON CONVERSION ERROR )
FROM   long_numbers

TO_NUMBER(VALUEDEFAULTNULLONCONVERSIONERROR)

null

112312321123123123123123123123123123112300000000000000000000000000000000000000000000000000000000000000000000000000000000000000

.0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000123456789012345678901234567890123456789

SELECT TO_BINARY_DOUBLE( value )
FROM   long_numbers

TO_BINARY_DOUBLE(VALUE)

1.1231232112312312E+126

1.1231232112312312E+125

1.2345678901234568E-110