Apex domains cannot have CNAME records.
Question and response
Question
dig akamaitech.net. NS
Answer
akamaitech.net. 5 NS zc.akamaitech.net.
akamaitech.net. 5 NS a1-193.akamaitech.net.
akamaitech.net. 5 NS ns4-193.akamaitech.net.
akamaitech.net. 5 NS ns2-193.akamaitech.net.
akamaitech.net. 5 NS ns5-193.akamaitech.net.
akamaitech.net. 5 NS a12-193.akamaitech.net.
akamaitech.net. 5 NS a3-193.akamaitech.net.
akamaitech.net. 5 NS zb.akamaitech.net.
akamaitech.net. 5 NS a5-193.akamaitech.net.
akamaitech.net. 5 NS zd.akamaitech.net.
akamaitech.net. 5 NS a6-193.akamaitech.net.
akamaitech.net. 5 NS a22-193.akamaitech.net.
akamaitech.net. 5 NS ns3-193.akamaitech.net.
Authority
The response has no authority records.
Additional
zc.akamaitech.net. 5 A 23.74.25.192
a1-193.akamaitech.net. 5 A 193.108.88.1
a6-193.akamaitech.net. 5 A 23.211.133.193
a12-193.akamaitech.net. 5 A 184.26.160.193
a22-193.akamaitech.net. 5 A 23.211.61.193
ns3-193.akamaitech.net. 5 A 23.61.199.193
ns4-193.akamaitech.net. 5 A 84.53.139.193
ns3-193.akamaitech.net. 5 AAAA 2600:1406:32:0:0:0:0:c1
ns4-193.akamaitech.net. 5 AAAA 2600:1480:1:0:0:0:0:c1
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0