public BigInteger sqrt ()

Returns the integer square root of this BigInteger. The integer square root of the corresponding mathematical integer n is the largest mathematical integer s such that s*s <= n. It is equal to the value of floor(sqrt(n)), where sqrt(n) denotes the real square root of n treated as a real. Note that the integer square root will be less than the real square root if the latter is not representable as an integral value.

Returns:  the integer square root of this

ArithmeticException    if this is negative. (The square root of a negative integer val is (i * sqrt(-val)) where i is the imaginary unit and is equal to sqrt(-1).)

Since:  9