18911499904 has 128 divisors (see below), whose sum is σ = 42603816960. Its totient is φ = 8284032000.

The previous prime is 18911499857. The next prime is 18911499913. The reversal of 18911499904 is 40999411981.

It is a tau number, because it is divible by the number of its divisors (128).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12351619 + ... + 12353149.

It is an arithmetic number, because the mean of its divisors is an integer number (332842320).

Almost surely, 2^18911499904 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18911499904, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21301908480).

18911499904 is an abundant number, since it is smaller than the sum of its proper divisors (23692317056).

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

18911499904 is a wasteful number, since it uses less digits than its factorization.

18911499904 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1870 (or 1858 counting only the distinct ones).

The product of its (nonzero) digits is 839808, while the sum is 55.

It can be divided in two parts, 18911 and 499904, that added together give a palindrome (518815).

The spelling of 18911499904 in words is "eighteen billion, nine hundred eleven million, four hundred ninety-nine thousand, nine hundred four".