Assuming the number is

, note that this number requires 144,001 digits in binary. On average, a single digit in base 60 requires about

binary digits. But obviously, we have to use a whole number of digits, so we round up to the next integer; in other words, given a number

in base 60 with

digits, we should expect

in base 2 to have

.
So, if the "conversion rate" from base 60 to base 2 is about 5.9069, then the reverse rate would be

, i.e. the solution to

. Again, we'd have to round up, so if

in base 2 has

digits, then

in base 60 should have

digits.
This means

in base 60 would have

digits.