498442857

498442857 is a notable number in the field of mathematics, particularly in the context of the divisibility rule for 7. This number is known as the "repeating 7" number because it consists of the digit 7 repeated seven times. The number is written as 498442857.

The divisibility rule for 7 states that a number is divisible by 7 if the difference between the number and the number formed by removing the last digit and multiplying it by 2 is also divisible by 7. For 498442857, this rule can be applied iteratively to determine its divisibility by 7.

The number 498442857 is also interesting because it is a palindromic number when read from left to right or right to left. This property makes it a palindrome in base 10.

In addition to its mathematical properties, 498442857 has been used in various contexts, including as a test case in algorithms and programs designed to check divisibility rules. Its simplicity and the fact that it is composed of a single repeating digit make it a useful number for educational purposes and for demonstrating mathematical concepts.