There is no area code +1 777 in North America (USA, Canada, etc.); it is unassigned. However, it will not be assigned as an ordinary area code, because it is reserved as an "easy to remember" code.
Many places have local numbers beginning with 777, but there is no 777 area code.
International telephone country code +7 is Russia and Kazakhstan, and a number beginning with +7 77 is a mobile phone from Kazakhstan.
(Apparently, some VoIP/SIP companies may assign numbers in area code +1 777 within their own networks, but those numbers cannot be dialed from the regular telephone network (landline or cellphone), because 777 is not a real area code. You can only dial those numbers within the private network of that particular VoIP or SIP company.)
(The plus sign means "insert your international access prefix here." From a GSM mobile phone, you can enter the number in full international format, starting with the plus sign. The most common prefix is 00, but North America (USA, Canada, etc.) uses 011, Japan uses 010, Australia uses 0011, and many other countries use different prefixes.)
The country code and area code of Qinzhou- GX, China is 86, (0)777.
The country code and area code of Cuernavaca- Mor., Mexico is 52, (01)777.
The country code and area code of Tomis Gomensoro, Uruguay is 598, (0)777.
All UK area codes begin with a 0. There is no area code 6010 in the UK, and there is no 06010 code either.
UK area code 020 is London.
There is no 01134 code in the UK.
There is no area code 20 in the UK
The country code and area code of Aberdeen, United Kingdom is 44, (0)1224.
There are five different cities named "Morelos" in Mexico, plus the state of Morelos, which has several different telephone area codes. Please specify the city and state. The area code for Cuernavaca, Morelos, is 777. Landline numbers are +52 777; mobile numbers are +52 1 777, with 7 more digits in either case.
In the UK, 0121 is the area code for Birmingham.
Cambridge is in area code 01223, or +44 1223 from outside the UK.
Until the early 1990's, area code +44 21 (or 021 within the UK) was Birmingham, which is now area code +44 121 (or 0121 within the UK). There has never been an area code +44 217 (or 0217) in the UK.