A cillion is not a recognized mathematical term or number. If you meant to refer to a "septillion," which is 1 followed by 24 zeros, or an "octillion," which is 1 followed by 27 zeros, please clarify. It's important to use standard numerical terminology to avoid confusion in mathematical discussions.
Three zeros... 39000
Possibly: 120 = 120.0000
Four zeros.
300,000,000 : nine zeros, :| .
500k written out is 500,000 There are 5 zeroes in 500,000
Zeros are very important and avoiding them without good reason can cause serious mathematical errors.
Three of them.
Three Zeros. 1000.
three zeros
There are 6 zeros.
Three zeros... 39000
Possibly: 120 = 120.0000
Four zeros.
300,000,000 : nine zeros, :| .
A thousand has three zeros... 1,000
three million = 3,000,000 (6 zeros)