A 64-bit number (as a hex string) that is randomly generated on the device’s first boot and should remain constant for the lifetime of the device. (The value may change if a factory reset is performed on the device.)
There are two ways to know your Android Device ID:
First Method: Enter *#*#8255#*#* in your phone dialer, you’ll be shown your android device ID.
Second Method: As another option, you can also use an Android app called “Android Device ID” that will quickly reveal the ID of your Android Device to you.
You can get hardware properties like Android SDK, Android Version, Android Brand, Manufacturer’s name and Android model by Settings -> About Phone. It should tell you most of what you want to know. Failing that, it will at least tell you a model name which you can then search google for more info.
The International Mobile Subscriber Identity or IMSI is used to identify the user of a cellular network and is a unique identification associated with all cellular networks. It is stored as a 64 bit field and is sent by the phone to the network. It is also used for acquiring other details of the mobile in the home location register (HLR) or as locally copied in the visitor location register. To prevent eavesdroppers identifying and tracking the subscriber on the radio interface, the IMSI is sent as rarely as possible and a randomly generated TMSI is sent instead.
The IMSI is used in any mobile network that interconnects with other networks. For GSM, UMTS and LTE network, this number is provisioned in the SIM card and for CDMA2000 in the phone directly or in the R-UIM card (the CDMA2000 analogue to a SIM card for GSM).
An IMSI is usually presented as a 15 digit number, but can be shorter. For example, MTN South Africa's old IMSIs that are still being used in the market are shown as 14 digits. The first 3 digits are the mobile country code (MCC), which are followed by the mobile network code (MNC), either 2 digits (European standard) or 3 digits (North American standard). The length of the MNC depends on the value of the MCC. The remaining digits are the mobile subscription identification number (MSIN) within the network's customer base.
An IMSI is usually presented as a 15 digit number, but can be shorter. The first 3 digits are the mobile country code (MCC), which are followed by the mobile network code (MNC), either 2 digits (European standard) or 3 digits (North American standard).
IMSI consists of three parts:
The IMSI (International Mobile Subscriber Identity) is a code used by the phone company to identify the SIM (phone user) on the mobile network.
The IMEI (International Mobile Station Equipment Identity) is an international "Serial number" for your phone (device itself) to properly identify it on the carriers network.