Unit systems SI prefixes

SI prefixes - there are 20 of them - are used to form names of decimal multiples and submultiples of SI units
It is important to note that the kilogram is the only SI unit with a prefix that is part of its name as well as a separate symbol. In other cases, multiple prefixes cannot be used. In the case of the kilogram, prefix names in the given table are used with the unit name "gram" and prefix symbols are used with the unit symbol "g". With this exception, any SI prefix can be used with any SI unit, including degrees Celsius and its symbol ° C for temperature.

SI unit system prefixes
Factor Prefix Symbol
1024 yotta Y
1021 zetta Z
1018 exa E
1015 peta P
1012 tera T
109 giga G
106 mega M
103 kilo k
102 hecto h
101 deca da
10-1 deci d
10-2 centi c
10-3 milli m
10-6 micro μ
10-9 nano n
10-12 pico p
10-15 femto f
10-18 atto a
10-21 zepto z
10-24 yocto y