The prefix exbi (Ei) is a prefix standardized by the International Electrotechnical Commission (IEC 60027-2) based on the exponentiation of the dual system
. The exbibinary, exbi, corresponds to a value of 2exp60. This is a 19-digit number. Numbers of this magnitude are allocated in file allocation tables (FAT) in the Extended Fiel Allocation Table (exFAT) or FAT64 version. Thus, a file system with 64 bytes corresponds to 16 exbi. This number results from 2exp60 multiplied by 2exp4.