if an alien probe landed on earth today, wouldn't it be a nice starting point to know that they use a mix of base 7, base 342, and base 61 for their number syst

if an alien probe landed on earth today, wouldn't it be a nice starting point to know that they use a mix of base 7, base 342, and base 61 for their number systems? I doubt that would be useful information. I would be most interested in knowing what number systems they used natively. Humans (almost?) universally use base ten.