ERROR: UNION types integer and character varying cannot be matched [SQL State=42804] - amazon-redshift

Question

I am doing union of two views but getting above error. Please help me to resolve this issue.
some values are hardcoded there and need to extract the same in final view.
I am using below query in redshift-
query:
DROP VIEW IF EXISTS jgbl.vw_jgvcc_crm_case_activity CASCADE;
CREATE OR REPLACE VIEW jgbl.vw_jgvcc_crm_case_activity
AS
SELECT case_number as "CASE Number",
parent_case_number as "Parent Case Number",
date_opened as "Date Opened",
number_of_questions as "Number of Questions",
case_record_type as "CASE Record Type",
NULL as "Sub Type",
category as "Category",
NULL as "Sub Category",
country as Country,
customer_type as "Customer Type",
primary_account_subtype as "Primary Account Subtype",
source as Source,
call_center_location as "Call Center Location",
region as Region,
customer_region as "Customer Region",
NULL as "AE",
NULL as "PQC",
'ASPAC' as datasource
FROM JG_ASPAC.vw_jgvcc_aspac_crm_activity
UNION ALL
SELECT case_num as "CASE Number",
NULL as "Parent Case Number",
open_dt as "Date Opened",
cast(num_of_ques as integer) as "Number of Questions",
rec_type_nm as "CASE Record Type",
rec_sub_type as "Sub Type",
cat_desc as "Category",
sctgy_desc as "Sub Category",
custm_latam_ctry_nm as Country,
acct_type as "Customer Type",
NULL as "Primary Account Subtype",
src_in as Source,
case when alph_fl='Y' then 'Alphanumeric' else 'LATAM Center' end as "Call Center Location",
'LATAM' as Region,
NULL as "Customer Region",
Case when rec_type_nm='AE/PQC' and rec_sub_type in ('ADVERSE EVENT','AE + PQC') then 'Y' else 'N' End as "AE",
Case when rec_type_nm='AE/PQC' and rec_sub_type in ('AE + PQC', 'PRODUCT QUALITY COMPLAINT') then 'Y' else 'N' End as "PQC",
'LATAM' as datasource
FROM JG_LTM.vw_jgvcc_latam_crm_activity as v2
--LEFT JOIN jgbl.dim_iso_reg_cntry as t1 on t1.region = v2.ctry_iso2_cd
with no schema binding;
error:
An error occurred when executing the SQL command:
select * from jgbl.vw_jgvcc_crm_case_activity limit 10
ERROR: Invalid digit, Value '.', Pos 1, Type: Integer
Detail:
error: Invalid digit, Value '.', Pos 1, Type: Integer
code: 1207
context: 1.0
query: 87576
location: :0
process: query1_562_87576 [pid=0]
----------------------------------------------- [SQL State=XX000]
1 statement failed.
Execution time: 4.81s