Guten Tag everyone

I am currently studying German language and at the moment my lecture are Numbers. I understand how to write down smaller ones but i am not 100 % sure if i understand how to write down large numbers correctly. Hope you guys can help me out here.

I will write down few numbers and then I would kindly ask someone to go over them and correct me, if anything is wrong.

3.521.694 - drei Millionen fünfhunderteinundzwanzigtausendsechshundertvierundneunzig
255.630.005 - zweihundertfünfundfünfzig Millionen sechshundertdreißigtausendfünf

And the longest one - 37.486.189.572
- siebenunddreißig Milliarden vierhundertsechsundachtzig Millionen einhundertneunundachtzigtausendfünfhundertzweiundsiebzig

Ist das richtig? Is that correct or am I doing something wrong?

Vielen Dank,
Toni