25×109

25 × 109 denotes the product of the integers 25 and 109. In decimal arithmetic, it evaluates to 2725.

Calculation: 109 × 25 = (100 + 9) × 25 = 2500 + 225 = 2725.

Prime factorization: 2725 = 25 × 109 = 5^2 × 109. The number 109 is a prime, so the prime factors of the product are 5, 5, and 109.

Properties: The product is odd, ends with the digits 25, and is divisible by 5 but not by 10. The last two digits reflect the factor 25, since 2725 = 25 × 109.

Context and usage: 25 × 109 serves as a straightforward example in basic arithmetic, illustrating multiplication by a two-digit number and the distributive property when expanding expressions. It can also be used to demonstrate modular considerations (for example, divisibility by 5) and to practice factorization and verification of results.