Apex domains cannot have CNAME records.
Question and response
Question
dig i19216811.com. NS
Answer
i19216811.com. 5 NS ns-1759.awsdns-27.co.uk.
i19216811.com. 5 NS ns-982.awsdns-58.net.
i19216811.com. 5 NS ns-93.awsdns-11.com.
i19216811.com. 5 NS ns-1239.awsdns-26.org.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0