987654312

987654312 is a nine-digit integer formed by the digits 1 through 9 exactly once. It is a permutation of the digits 1–9 and can be described as a pandigital number in base ten. The sequence is close to a descending order, with the final two digits swapped from the familiar 987654321 to 987654312.

Mathematical properties of the number include its divisibility characteristics and factorization. The sum of its digits is 45, which makes the number divisible by 9 (and therefore by 3 as well). A straightforward factorization is 987,654,312 = 8 × 123,456,789 = 9 × 109,739,368. As a result, the number is composite.

Context and usage in mathematics and computing. As a 1–9 pandigital number, 987654312 is often cited in discussions of permutation patterns and pandigital conventions. Its relationship to 123,456,789 (the ascending pandigital sequence) and to 987,654,321 (the descending sequence) is sometimes noted in examples illustrating digit arrangements, modular arithmetic, or tests of numerical algorithms. Beyond theoretical interest, such numbers frequently appear in programming exercises that involve generating, sorting, or validating pandigital permutations.