I want to add up all numbers from 1 to 1000000.

```
range = 1..1000000
println range.each { it * it }.sum()

```

As a result I get 1784293664 instead of 500000500000. I assume, I need a BigInteger. But when I try

```
range = 1..1000000
println range.each { it * it }.sum().toBigInteger()

```

nothing changes. 

Where is my mistake?