% APNIC found the following authoritative answer from: whois.ripe.net

% This is the RIPE Database query service.
% The objects are in RPSL format.
%
% The RIPE Database is subject to Terms and Conditions.
% See https://docs.db.ripe.net/terms-conditions.html

% Note: this output has been filtered.
%       To receive output for a database update, use the "-B" flag.

% Information related to '2a02:587:5400::/40'

% Abuse contact for '2a02:587:5400::/40' is 'abuse@ote.gr'

inet6num:       2a02:587:5400::/40
netname:        GR-OTE-CUSTOMERS
country:        GR
admin-c:        OIA10-RIPE
tech-c:         OIA10-RIPE
status:         AGGREGATED-BY-LIR
assignment-size: 56
mnt-by:         OTE-ADMIN-MNT
mnt-by:         OTENET-GR-MNT
created:        2021-09-17T08:25:21Z
last-modified:  2021-09-17T08:25:21Z
source:         RIPE

role:           OTE IP ADM
address:        Ote SA (Hellenic Telecommunications Organisation)
address:        Kifissias 99
address:        GR-15124 Athens
address:        Greece
fax-no:         +30 210 6116215
admin-c:        AV323-RIPE
tech-c:         PP5896-RIPE
nic-hdl:        OIA10-RIPE
abuse-mailbox:  abuse@ote.gr
mnt-by:         OTE-ADMIN-MNT
created:        2009-11-09T10:43:59Z
last-modified:  2021-07-05T06:12:26Z
source:         RIPE # Filtered

% Information related to '2a02:587:5400::/38AS6799'

route6:         2a02:587:5400::/38
descr:          OTEv6
origin:         AS6799
mnt-by:         OTE-ADMIN-MNT
created:        2016-02-19T13:32:39Z
last-modified:  2016-02-19T13:32:39Z
source:         RIPE

% This query was served by the RIPE Database Query Service version 1.114 (ABERDEEN)

Search for
IP address lookups			Miscellaneous queries
-l	1st level less specific		-i	Inverse attributes	None admin-c admin-c,tech-c,zone-c author cross-mnt cross-nfy local-as mbrs-by-ref member-of mnt-by mnt-lower mnt-nfy mnt-routes notify nserver origin person referral-by rev-srv sub-dom tech-c upd-to zone-c
-L	All less specific		-T	Object types	All as-block as-set aut-num domain filter-set inet-rtr inet6num inetnum irt key-cert mntner peering-set person role route route-set rtr-set
-m	1st level more specific
-M	All more specific		Query hints Include "AS" in front of an AS number. Example: AS4808 Include "-t" (template only) or "-v" (template and description) in front of an object name to view the template Example: -t inetnum
-x	Exact match only
-d	Associated reverse domain