In NATIONAL format, aka ITU-T Recommendation E123, the number is written 09 083 6583
Likewise, in E123 INTERNATIONAL formal, it is written +234 9 083 6583
In E.164 standard format, the number is written +23490836583. E164 format is as per E123 INTERNATIONAL format but with no formatting applied.
In RFC3966 standard format, the number is written tel:+234-9-083-6583. FC3966 is as per INTERNATIONAL format, but with all spaces and other separating symbols replaced with a hyphen, and with any phone number extension appended with ";ext=". It also will have a prefix of "tel:" added .
To dial this number from within the United States, one would dial 011 234 9 083 6583
To dial this number from inside the United Kingdom or the European Union, one would dial 00 234 9 083 6583
Numbers like +23490836583 may be located in the Africa/Lagos timezone, where the local time is currently Saturday the 4th of February 2023 10:27:01 PM.