Update 15_payment_requests.asciidoc

2,500 micro bitcoin equals 250,000 satoshis

15_payment_requests.asciidoc

@@ -85,7 +85,7 @@ eyes, while the rest of it just looks like a random set of strings. The part
 that is somewhat parsable by a human is referred to as the _human-readable prefix_. It allows a human to quickly extract some relevant information from a
 payment request at a glance. In this case, we can see that this payment is for
 the mainnet instance of the Lightning Network (`lnbc`), and is requesting 2,500
-uBTC (microbitcoin), or 25,000,000 satoshis. The latter potion is referred
+uBTC (microbitcoin), or 250,000 satoshis. The latter potion is referred
 to as the data portion and uses an extensible format to encode the
 information required to complete a payment.