Telephone country code +971 is the United Arab Emirates, and a number beginning with +971 55 is a mobile on the Du network.
(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.)
That is not a valid mobile number. There is no country code starting with a sequence of zeros.
Country code +60 is Malaysia, but a number beginning with +60 4 is a geographic number (i.e., a landline), not a mobile.
That's not a valid number.
Country code +503 is El Salvador, and +503 720 xxxxx is a mobile number.
Idea
Country code +233 is Ghana, and a number beginning +233 20 is a mobile.
Country code +39 is Italy, and +39 392 is an H3G mobile
The easiest way to store numbers on your mobile is in international format. In the case of Tunisia, start with country code +216, including the plus sign. The mobile network will then insert the appropriate prefix, wherever you are calling from. If you store the number starting with 00216, your call or text may be misrouted if you are roaming in a country that uses a different international access prefix.
Egypt is country code +20, and a number beginning with +20 106 is a Vodafone mobile.
If you're calling a UK mobile that is physically in Spain, just dial the UK mobile number. It does not matter where the mobile is physically located. If you're calling a Spanish mobile, dial 00 (the prefix for outbound international calls from the UK), then 34 (the country code for Spain), and then the 9-digit Spanish mobile number. If you're calling from a GSM mobile phone, you can dial +34 (including the plus symbol) instead of 00 34.
0091 is the country code for India... 94 indicates a mobile number.
Nowhere. Any UK number starting with 7 will be a mobile (cell) phone number.