90091090991 has 24 divisors (see below), whose sum is σ = 101590654032. Its totient is φ = 79804771200.

The previous prime is 90091090949. The next prime is 90091091009. The reversal of 90091090991 is 19909019009.

It is a de Polignac number, because none of the positive numbers 2^k-90091090991 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (90091092991) 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, 732731 + ... + 846803.

It is an arithmetic number, because the mean of its divisors is an integer number (4232943918).

Almost surely, 2^90091090991 is an apocalyptic number.

90091090991 is a deficient number, since it is larger than the sum of its proper divisors (11499563041).

90091090991 is a wasteful number, since it uses less digits than its factorization.

90091090991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 114263 (or 114252 counting only the distinct ones).

The product of its (nonzero) digits is 59049, while the sum is 47.

The spelling of 90091090991 in words is "ninety billion, ninety-one million, ninety thousand, nine hundred ninety-one".