5×1997

5×1997 is a simple arithmetic expression that multiplies the integer 5 by the prime number 1997. The result of this operation is 9985, as calculated by the standard multiplication algorithm: five times one thousand nine hundred and ninety‑seven equals nine thousand nine hundred and eighty‑five.

1997 is a prime number, meaning it has no positive divisors other than 1 and itself. When multiplied by 5, a prime factor of 5, the product 9985 has the prime factorization 5 × 1997. Thus, the only prime factors of 9985 are 5 and 1997. The number 9985 is therefore composite and is congruent to 0 modulo 5, which is expected because any integer multiplied by 5 is divisible by 5.

The expression 5×1997 occasionally appears in educational contexts, such as example problems in elementary mathematics, quizzes on multiplication or prime numbers, and as a test case in programming exercises that involve large integer manipulation or prime factorization. It also serves as a straightforward demonstration of the distributive property when written in expanded form (5×2000 – 5×3).

In historical documentation and commercial contexts, the years 1997 and 1998 were noted for significant events, but the specific mathematical product 5×1997 has no inherent historical or cultural significance beyond its role as a basic arithmetic fact. Nonetheless, the result 9985 is sometimes used in novelty contexts, such as sums that form near‑round thousand figures or in puzzles that ask for the product of small integers and centuries’ prime numbers.