use Math::Base85 qw(from_base85 to_base85);

$str = '0b0000000100100011010001010110011110001001101010111100110111101111';

$bint = Math::BigInt->new($str);
$b85str = to_base85($bint);
$bint2 = from_base85($b85str);
print $bint2->as_bin();