Integer to string conversion function in sql

Question

I have a number as follows: 13901210 I want the output to give the following result 1390/12/10

Input function: a number of bigint Output: a string

How do I create this function?

Answer 1

I wonder why no one suggested this Simple Query

declare @input bigint=13901210

select REPLACE(Convert(varchar,Convert(date,CONVERT(varchar,@input))),'-','/')

SQL Fiddle