Septrillion is not a month but is a number figure. Septrillion in a number like million that is used to discuss a huge number. The number has too many zero's to bother with but it 10008. As 10001 is one thousand or a kilo it can be used to express megabytes for computers. Septrillion is as said 10008, i is said also as a yotta can be used to express yottabytes. A number too large for technology to yet create for a computer's memory.
Its About 1000000000000000000000000 Metres (1 Septrillion)(24 Zeros)
The name of the power of 1000 after septillion (note the slight alteration in spelling), is octillion.
sextrillion and one! But I assume you want to know the next major unit, which is septrillion (equal to a thousand sextrillions).