177777777
The number 177,777,777 is a nine-digit integer. It is an odd number and is divisible by 9, as the sum of its digits (1+7+7+7+7+7+7+7+7) equals 56, which is a multiple of 9. In base 10, it is written as 177,777,777. In scientific notation, it is expressed as 1.77777777 x 10^8. The number 177,777,777 is also a repdigit, meaning it consists of repeated digits. It is not a prime number, as it has factors other than 1 and itself, such as 3, 9, and 19,753,191. The number 177,777,777 is often used in mathematical and computational contexts for testing algorithms and software due to its unique properties and the challenges it presents.