ORA-12012: error on auto execute of job ORA-12008: error in materialized view refresh path ORA-01722: invalid number

Errors in file /u01/app/oracle/diag/rdbms/db/db/trace/db_j000_31458.trc:
ORA-12012: error on auto execute of job 111816
ORA-12008: error in materialized view refresh path
ORA-01722: invalid number
ORA-06512: at "SYS.DBMS_SNAPSHOT", line 2821
ORA-06512: at "SYS.DBMS_SNAPSHOT", line 3058
ORA-06512: at "SYS.DBMS_IREFRESH", line 687
ORA-06512: at "SYS.DBMS_REFRESH", line 195
ORA-06512: at line 1


Approach :

select job, schema_user, what from dba_jobs where job='111816';

  JOB SCHEMA_USER WHAT
111816 DB_PROD      dbms_refresh.refresh('"DB_PROD"."MV_CUST"');



Open the above mentioned materialized view "MV_CUST", in select query, one of the condition getting failed with "INVALID NUMBER". By digging down, found that, in one column having (its datatype VARCHAR) instead of number there was CHARACTER and this row getting compared with number.