19999999998 has 96 divisors (see below), whose sum is σ = 48609759744. Its totient is φ = 5890320000.

The previous prime is 19999999967. The next prime is 20000000089. The reversal of 19999999998 is 89999999991.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2195433 + ... + 2204523.

It is an arithmetic number, because the mean of its divisors is an integer number (506351664).

Almost surely, 2^19999999998 is an apocalyptic number.

19999999998 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 19999999998, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24304879872).

19999999998 is an abundant number, since it is smaller than the sum of its proper divisors (28609759746).

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

19999999998 is a wasteful number, since it uses less digits than its factorization.

19999999998 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9422 (or 9419 counting only the distinct ones).

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

It can be divided in two parts, 1 and 9999999998, that added together give a palindrome (9999999999).

The spelling of 19999999998 in words is "nineteen billion, nine hundred ninety-nine million, nine hundred ninety-nine thousand, nine hundred ninety-eight".