db.r6g.4xlarge is an Amazon DocumentDB size with 16 vCPUs, 128 GiB memory (AWS Graviton2). In US East (N. Virginia) it costs $2.105 per hour on demand ($1,536.80 per month) for Standard storage. It is sold in 34 regions.
Prices by region
USD per hour, Standard storage. Reserved prices are no upfront, standard. Cheapest on-demand first.