97654321

97654321 is the eight-digit integer 97,654,321. It features a descending sequence of digits from 9 to 1 with the digit 8 omitted, a pattern sometimes used to illustrate decimal place value and digit arrangement in teaching materials.

Numerical properties: The number is odd, since it ends in 1. Its digit sum is 9+7+6+5+4+3+2+1 = 37, giving a digital root of 1 and a residue of 1 modulo 9. Because the sum of digits is not a multiple of 3, it is not divisible by 3 or 9. It is not divisible by 2 or 5, as it ends with 1. The last three digits are 321, which implies it is not divisible by 8. The complete prime factorization requires calculation and is not immediately evident.

Context and usage: In mathematics and computer science, 97,654,321 may be used as an example of a large, nontrivial eight-digit number for exercises involving arithmetic, modular arithmetic, or digit-pattern analysis. It does not correspond to a widely cited historical event, product code, or standardized identifier in public sources.

Related topics: Numbers with descending digits are sometimes discussed in examples of order and decimal representation, including references to other large eight- or nine-digit numbers that demonstrate digit patterns.