990908091 has 24 divisors (see below), whose sum is σ = 1458684864. Its totient is φ = 648054000.

The previous prime is 990908089. The next prime is 990908099. The reversal of 990908091 is 190809099.

990908091 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 990908091 - 2¹ = 990908089 is a prime.

It is not an unprimeable number, because it can be changed into a prime (990908099) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 148080 + ... + 154626.

It is an arithmetic number, because the mean of its divisors is an integer number (60778536).

Almost surely, 2^990908091 is an apocalyptic number.

990908091 is a deficient number, since it is larger than the sum of its proper divisors (467776773).

990908091 is a wasteful number, since it uses less digits than its factorization.

990908091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6871 (or 6868 counting only the distinct ones).

The product of its (nonzero) digits is 52488, while the sum is 45.

The square root of 990908091 is about 31478.6926507439. The cubic root of 990908091 is about 996.9601322342.

The spelling of 990908091 in words is "nine hundred ninety million, nine hundred eight thousand, ninety-one".