10909090909091

10909090909091 is a decimal integer notable for its distinctive digit pattern. It consists of 14 digits arranged as 1,0,9,0,9,0,9,0,9,0,9,0,9,1, producing an alternating sequence of zeros and nines with a leading and trailing one. In terms of magnitude, it lies in the tens of trillions.

Basic arithmetic properties of the number can be inferred from its digit sum and parity. The sum of its digits is 56, which shows the number is not divisible by 3. The last digit is 1, so it is odd and not divisible by 2 or 5. A quick check for divisibility by 11 using the alternating-sum rule yields a nonzero remainder, indicating it is not divisible by 11. Beyond these simple tests, there is no widely documented mathematical significance associated with this specific integer.

As a large integer with a recurring digit pattern, 10909090909091 is sometimes encountered in discussions of digit-pattern analysis, modular arithmetic examples, or as a test input in software and algorithm demonstrations. It serves as a representative case illustrating how numbers with alternating digits behave under common divisibility checks and basic arithmetic operations.

See also: numbers with alternating digit patterns, divisibility tests, large integer examples.