That is not a valid telephone number.
The number +44 171 900 1234 would have changed to +44 20 7900 1234 back in 2000. However, since that number would now be at least 12 years out of date, it should be considered unreliable.
+44 is the country code for the United Kingdom, including England. +44 78xxx xxxxxx will be a mobile phone. It could be anywhere in England, Wales, Scotland or Northern Ireland and is not linked to a specific geographic area.
+44 7749 xxxxxx (or 07749 xxxxxx when calling within the UK) is a batch of mobile phone numbers owned by O2. They are not linked to any particular geographical area and could be anywhere in England, Wales, Scotland or Northern Ireland.
The area code 01341 is for Barmouth, Dolgellau, in the UK. The full number should be written as (01341) xxxxxx or as +44 1341 xxxxxx.
44 is the country code for the United Kingdom, so I guess the full number is: +44 7974 xxxxxx in international format or 07974 xxxxxx when dialling within the UK. If so, 07974 (the zero is dropped when dialling from overseas) is a prefix used for mobile phones. As mobile phones in the UK are not linked to specific geographic areas, it could be a mobile owned by somebody anywhere in England, Wales, Scotland or Northern Ireland.
That number belongs to a mobile (cell) phone - not a specific area. 44 is the country code for the UK. The next digit (7) indicates it is a non-geographic number.
This is a UK personal "follow-me" phone number so it could be forwarded to almost anywhere in the world, not necessarily London.
-340
As dialled from abroad, 011 44 7xxx xxxxxx or 00 44 7xxx xxxxxx would indicate it's a mobile (cell) phone number. 01447 xxxxxx as an area code was "Kingston Communications Premium Rate" in the late 1990s and it's to be assumed those moved to an 090x xxx xxxx number in the Big Number Change in 2000.
it is my number
01332
from Ireland dial: 0044(united kingdom) 28(northern Ireland) xx(local area) xxxxxx(phone number) ta-da.
This is a mobile (cell) phone number.