Apex domains cannot have CNAME records.
Question and response
Question
dig akam.net. NS
Answer
akam.net. 5 NS a1-67.akam.net.
akam.net. 5 NS a6-67.akam.net.
akam.net. 5 NS a22-67.akam.net.
akam.net. 5 NS a12-67.akam.net.
akam.net. 5 NS a11-67.akam.net.
akam.net. 5 NS a4-67.akam.net.
akam.net. 5 NS a18-67.akam.net.
akam.net. 5 NS a28-67.akam.net.
Authority
The response has no authority records.
Additional
a1-67.akam.net. 5 A 193.108.91.67
a4-67.akam.net. 5 A 72.246.46.67
a6-67.akam.net. 5 A 23.211.133.67
a11-67.akam.net. 5 A 84.53.139.67
a12-67.akam.net. 5 A 184.26.160.67
a18-67.akam.net. 5 A 95.101.36.67
a22-67.akam.net. 5 A 23.211.61.67
a28-67.akam.net. 5 A 95.100.173.67
a1-67.akam.net. 5 AAAA 2600:1401:2:0:0:0:0:43
a4-67.akam.net. 5 AAAA 2600:1480:9000:0:0:0:0:43
a6-67.akam.net. 5 AAAA 2600:1401:1:0:0:0:0:43
a11-67.akam.net. 5 AAAA 2600:1480:1:0:0:0:0:43
a12-67.akam.net. 5 AAAA 2600:1480:f000:0:0:0:0:43
a18-67.akam.net. 5 AAAA 2600:1480:4800:0:0:0:0:43
a22-67.akam.net. 5 AAAA 2600:1480:7800:0:0:0:0:43
a28-67.akam.net. 5 AAAA 2600:1480:d800:0:0:0:0:43
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0