990081808 has 20 divisors (see below), whose sum is σ = 1984432140. Its totient is φ = 477970304.

The previous prime is 990081803. The next prime is 990081809. The reversal of 990081808 is 808180099.

It can be written as a sum of positive squares in 2 ways, for example, as 588159504 + 401922304 = 24252^2 + 20048^2 .

It is not an unprimeable number, because it can be changed into a prime (990081803) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1066435 + ... + 1067362.

It is an arithmetic number, because the mean of its divisors is an integer number (99221607).

Almost surely, 2^990081808 is an apocalyptic number.

It is an amenable number.

990081808 is an abundant number, since it is smaller than the sum of its proper divisors (994350332).

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

990081808 is a wasteful number, since it uses less digits than its factorization.

990081808 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2133834 (or 2133828 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 43.

The square root of 990081808 is about 31465.5654327075. The cubic root of 990081808 is about 996.6829453139.

The spelling of 990081808 in words is "nine hundred ninety million, eighty-one thousand, eight hundred eight".