The brain operates on the next order higher.
Although it is impossible to calculate precisely, it is postulated that the human brain operates at one exaFLOP (1018), equivalent to billions of billions of calculations per second.
When we discuss supercomputers or even computers in general, we refer to meticulously designed machines based on logic, reproducibility, predictability, and math over data.
On the other hand, the human brain is a tangled, seemingly random mess of neurons that do not behave predictably. Still, the same architecture can be ported into a computer system.
The brain is both hardware and software, and the computer is the same; even if the architecture and the functionalities are quite different, both execute operation over data.
One of the most crucial difference is that inside the brain, the same interconnected areas, linked by billions of neurons and perhaps trillions of glial cells, can perceive, interpret, store, analyze, and redistribute at the same time. By their very definition and fundamental design, computers have some parts for processing and others for memory; the brain does not make that separation, making it hugely efficient.
The computing power of the brain is achieved in an extraordinary efficiency compared with supercomputers. The brain's power consumption in the order of 10-20 watts for 1018 operations per second. In a conventional supercomputer with the same computational power (based on CPUs and accelerators), the power consumption is in the order of 50 Megawatts!
The brain is millions of times more efficient than today computers!