How to add commas to a large integer number and add zeros after first comma

Question

Consider an integer number @num = 27565. I want to display it as 27,000

I tried this in my rails console:

number_with_delimiter(12345678)   # => 12,345,678

But I am getting this error:

NoMethodError: undefined method `number_with_delimiter' for main:Object

Some of the examples are:

12345678   # => 12,000,000
27565   # => 27,000

UPDATE

---

The NoMethodError was fixed by following:

How to use all view and helper methods inside of Rails console for Rails 2.x and 3.x?

But my second question, i.e how to add zeros after first comma, was not answered.