90909991000 has 32 divisors (see below), whose sum is σ = 212729381280. Its totient is φ = 36363996000.

The previous prime is 90909990947. The next prime is 90909991009. The reversal of 90909991000 is 19990909.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (90909991009) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 45453996 + ... + 45455995.

It is an arithmetic number, because the mean of its divisors is an integer number (6647793165).

Almost surely, 2^90909991000 is an apocalyptic number.

It is an amenable number.

90909991000 is an abundant number, since it is smaller than the sum of its proper divisors (121819390280).

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

90909991000 is a wasteful number, since it uses less digits than its factorization.

90909991000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 90910012 (or 90909998 counting only the distinct ones).

The product of its (nonzero) digits is 59049, while the sum is 46.

The spelling of 90909991000 in words is "ninety billion, nine hundred nine million, nine hundred ninety-one thousand".