Well, if Superman is as strong as a trillion men (planetary strength? probably stronger), then he'd be as strong as a 100 billion - 250 billion silverbacks (probably stronger).
__________________
Shinier than a speeding bullet.
Let's say 10 strong men can benchpress 1 ton. It would therefore take 66 sextillion strong men to benchpress the Earth, once (for the moment, we'll ignore the stamina end of Superman's feat).
This means: if we could summon the strength of every human being, and every silverback gorilla who has ever lived, it would still be a minute fraction of Superman's might.
Fun with numbers.
__________________
Shinier than a speeding bullet.