Because a 6-digit code is strictly numerical, the math is simple: 10610 to the sixth power Range: 000,000 to 999,999 Total count: 1,000,000 possible codes.
If you are a developer or security professional, here are the golden rules to render OTP wordlists useless:
2.1 The Keyspace A 6-digit numerical password has a fixed length $L=6$ using digits $0-9$. The total keyspace ($K$) is calculated as: $$K = 10^6 = 1,000,000 \text possible combinations.$$
Understanding 6-Digit OTP Wordlists: Security, Research, and Risks
A complete wordlist containing every OTP from 000000 to 999999 occupies approximately as plain text (1 million lines × 6 digits + newline). This is trivial to store or transmit.