doubt on data types ( cnipf dtx)

data : a1 type i .

now howmany values can i hold it seems it can hold 4 bytes .

1 byte = 8 bits

1bit = 1 / 0

so 8 bits = 8 * 1 = 8 (abcdefgh)

so 4 bytes = 4 * 8 = 32 bits.

it means a1 can hold 9999999999999999999999999999999

please explain if it is not true.