99999199998 has 64 divisors (see below), whose sum is σ = 228481827840. Its totient is φ = 32399870400.

The previous prime is 99999199987. The next prime is 99999199999. The reversal of 99999199998 is 89999199999.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (99999199999) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 516661 + ... + 683327.

It is an arithmetic number, because the mean of its divisors is an integer number (3570028560).

Almost surely, 2^99999199998 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 99999199998, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (114240913920).

99999199998 is an abundant number, since it is smaller than the sum of its proper divisors (128482627842).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

99999199998 is a wasteful number, since it uses less digits than its factorization.

99999199998 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 166990 (or 166984 counting only the distinct ones).

The product of its digits is 3099363912, while the sum is 90.

Subtracting from 99999199998 its reverse (89999199999), we obtain a palindrome (9999999999).

The spelling of 99999199998 in words is "ninety-nine billion, nine hundred ninety-nine million, one hundred ninety-nine thousand, nine hundred ninety-eight".