Does eNodeB ID should have a specific digit length?

Specs & Protocol Testing
1

Hi Experts.
Does eNodeB ID should have a specific digit length?

2

I see its 7 digit.

3

In ECGI EnodeB ID can have either 20 bits or 28 bits.

Details here :LTE Identifiers

4

How to Compute IMEI from IMEISV: