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.

` 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)` .) |

Diagram: BigInteger, BigDecimal