00 isn't part of the code, it is a commonly used international access prefix
+20 is the telephone country code for Egypt
1 is the beginning of the telephone number in Egypt (01 in domestic format)
+20 13 is a landline number in Benha
+20 10 is a Vodafone mobile number
+20 11 is an Etisalat mobile number
+20 12 is a Mobinil mobile number
Note that all mobile phone numbers in Egypt changed in 2011. See the related link.
(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.)
Leichtenstein is telephone country code +423.
where is telephone country code 1816
That is not a country code.
00120-P1
The postal code for Vatican City is 00120 in the Italian system.
Fiji has telephone country code +679.
Country code +57 is Colombia.
Gibraltar is country code +350.
Moldova is country code +373.
Slovenia is country code +386.
Vanuatu is country code +678.
Niue is country code +683.