In 2014 Randall Munroe estimated that Google stores 10 exabytes of data across all of its operations. See list of SI prefixes. If CPUs are topping out at gigahertz then single operations aren’t going to subceed the order of nanoseconds.

                    1 000 kilo | milli .001
1 000 000 mega | micro .000 001
1 000 000 000 giga | nano  .000 000 001
1 000 000 000 000 tera | pico  .000 000 000 001
1 000 000 000 000 000 peta | femto .000 000 000 000 001
1 000 000 000 000 000 000  exa | atto  .000 000 000 000 000 001


You might find it easier to think of them in multiples of 1000. You might be tempted to use binary prefixes to be precise (kibi, mebi, gibi) but most people won’t know what you’re on about. Also everybody uses 1000^3 rather than 2^20 because it makes your performance look better.

1000^ 1000^
kilo 1 milli -1
mega 2 micro -2
giga 3 nano -3
tera 4 pico -4
peta 5 femto -5
exa 6 atto -6