What is a Reference number in Purchase response CSV compose of?

Hello,

I am new to Moneris, I am wondering what that Reference number in Moneris Response Compose of?

I uploaded this 

purchase,31,13.00,4242424242424242,2204,1

The response is below.

"31,660158050010010210,027,01,984400,16:41:24,2019-07-08,00,true,APPROVED           *                    =,13.00,V,71-0_14,false,,null"

What is this reference number compose of? 660158050010010210

Thanks