789101112

789101112 is the decimal representation obtained by concatenating the consecutive integers 7 through 12: 7, 8, 9, 10, 11, 12. Interpreted as a single number, it equals 789,101,112.

The nine-digit number is even, and the sum of its digits is 30, so it is divisible by 2 and 3, hence by 6. Because the last three digits form 112, it is also divisible by 8, and thus by 24. Its prime factorization begins with 2^3 × 3 × 32,879,213, with the final cofactor being odd and not divisible by 3. The complete factorization beyond these factors may involve larger primes.

In recreational mathematics, 789101112 is often cited as an example of a finite segment formed by concatenating consecutive integers. It also appears as a fragment of the Champernowne constant, a decimal formed by concatenating all positive integers in order (0.12345678910111213…). Such concatenations illustrate how simple digit patterns can arise from stringing together successive integers and are used in puzzles, algorithmic parsing tests, and explorations of number structure.

See also Champernowne constant; concatenation of integers; number theory.

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