src/Numbers/Number.php
public function getDigit($n, $base = 10)
    {
        $m = abs($this->number) / pow($base, $n);
        return $m % $base;
    }
public function getDigit($n, $base = 10)
    {
        $m = abs($this->number) / pow($base, $n);
        return $m % $base;
    }
Returns the n-th digit of the number in base $n, where n is the exponent of
$base in the expansion of $this->number in base $base

As usual keep in mind that float precision is limited, so there can be errors
when the digit is of a magnitude 12-13 times smaller than the magnitude of
the numnber.

@param int $n
@param int $base
@return float