91021288944 has 80 divisors (see below), whose sum is σ = 243317239200. Its totient is φ = 29285695488.

The previous prime is 91021288937. The next prime is 91021288993. The reversal of 91021288944 is 44988212019.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a junction number, because it is equal to n+sod(n) for n = 91021288893 and 91021288902.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6274852 + ... + 6289340.

It is an arithmetic number, because the mean of its divisors is an integer number (3041465490).

Almost surely, 2^91021288944 is an apocalyptic number.

It is an amenable number.

91021288944 is an abundant number, since it is smaller than the sum of its proper divisors (152295950256).

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

91021288944 is a wasteful number, since it uses less digits than its factorization.

91021288944 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19042 (or 19036 counting only the distinct ones).

The product of its (nonzero) digits is 331776, while the sum is 48.

The spelling of 91021288944 in words is "ninety-one billion, twenty-one million, two hundred eighty-eight thousand, nine hundred forty-four".