Not at the paid version 4o here 

The total supply of Bitcoin is capped at 21 million bitcoins. Each bitcoin is divisible into 100,000,000 Satoshis. To find the total number of Satoshis in the total supply of Bitcoin, you multiply the total number of bitcoins by the number of Satoshis per bitcoin:

\[ 21,000,000 \text{ bitcoins} \times 100,000,000 \text{ Satoshis/bitcoin} = 2,100,000,000,000,000 \text{ Satoshis} \]

So, the total bitcoin supply has 2,100,000,000,000,000 Satoshis.

How to pronounce that number? 

The number 2,100,000,000,000,000 is pronounced as:

"Two quadrillion, one hundred trillion."

So, you can say:

"Two quadrillion, one hundred trillion Satoshis."