(PHP 5, PHP 7 >= 5.6.0)
gmp_root — Take the integer part of nth root
Takes the nth root of a and
returns the integer component of the result.
Either a GMP number resource in PHP 5.5 and earlier, a GMP object in PHP 5.6 and later, or a numeric string provided that it is possible to convert the latter to a number.
The positive root to take of a.
The integer component of the resultant root, as a GMP number.