9991438404 has 12 divisors (see below), whose sum is σ = 23313356304. Its totient is φ = 3330479464.

The previous prime is 9991438399. The next prime is 9991438427. The reversal of 9991438404 is 4048341999.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (12).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 416309922 + ... + 416309945.

It is an arithmetic number, because the mean of its divisors is an integer number (1942779692).

Almost surely, 2^9991438404 is an apocalyptic number.

It is an amenable number.

9991438404 is an abundant number, since it is smaller than the sum of its proper divisors (13321917900).

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

9991438404 is a wasteful number, since it uses less digits than its factorization.

9991438404 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 832619874 (or 832619872 counting only the distinct ones).

The product of its (nonzero) digits is 1119744, while the sum is 51.

The square root of 9991438404 is about 99957.1828534598. The cubic root of 9991438404 is about 2153.8196678319.

The spelling of 9991438404 in words is "nine billion, nine hundred ninety-one million, four hundred thirty-eight thousand, four hundred four".