Tel Aviv is in Israeli area code 03, which is +972 3 in international format.
(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 for Israel is 972.
Leichtenstein is telephone country code +423.
where is telephone country code 1816
That is not a country code.
The country code and area code of Haifa, Israel is 972, (0)4.
The country code and area code of Hasharon, Israel is 972, (0)9.
The country code and area code of Hashfela, Israel is 972, (0)8.
Country code +972 is Israel.
Country code +57 is Colombia.
Country code 52 is Mexico.
Fiji has telephone country code +679.
Gibraltar is country code +350.