How to find a value is numeric or not in Oracle?

Scenario:

Value               Result
12345              Number
12Z3A             Alpha Numeric

Simple Query:

select '12345' input,
DECODE( TRANSLATE('12345','0123456789',' '), NULL, 'Number','Alpha Numeric') Result
 from dual

select '12Z3A' input,
DECODE( TRANSLATE('12Z3A','0123456789',' '), NULL, 'Number','Alpha Numeric') Result
 from dual;