91081805120 has 42 divisors (see below), whose sum is σ = 216901404906. Its totient is φ = 36430562560.

The previous prime is 91081805117. The next prime is 91081805149. The reversal of 91081805120 is 2150818019.

It can be written as a sum of positive squares in only one way, i.e., 72865444096 + 18216361024 = 269936^2 + 134968^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 5390285 + ... + 5407155.

Almost surely, 2^91081805120 is an apocalyptic number.

It is an amenable number.

91081805120 is an abundant number, since it is smaller than the sum of its proper divisors (125819599786).

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

91081805120 is an frugal number, since it uses more digits than its factorization.

91081805120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33759 (or 16878 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 35.

The spelling of 91081805120 in words is "ninety-one billion, eighty-one million, eight hundred five thousand, one hundred twenty".