10 to the 9th power, written mathematically as 109, equals 1,000,000,000.
This value is derived from multiplying the number 10 by itself a total of nine times:
10 × 10 × 10 × 10 × 10 × 10 × 10 × 10 × 10 = 1,000,000,000.
This exponential notation is a concise way of expressing large numbers, and 109 specifically represents one billion. Understanding powers of ten is crucial in fields such as science and finance, where large quantities are frequently encountered.