9891765928 has 32 divisors (see below), whose sum is σ = 21423346560. Its totient is φ = 4231770880.

The previous prime is 9891765887. The next prime is 9891765931. The reversal of 9891765928 is 8295671989.

It is a self number, because there is not a number n which added to its sum of digits gives 9891765928.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3304576 + ... + 3307567.

It is an arithmetic number, because the mean of its divisors is an integer number (669479580).

Almost surely, 2^9891765928 is an apocalyptic number.

It is an amenable number.

9891765928 is an abundant number, since it is smaller than the sum of its proper divisors (11531580632).

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

9891765928 is a wasteful number, since it uses less digits than its factorization.

9891765928 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6612177 (or 6612173 counting only the distinct ones).

The product of its digits is 19595520, while the sum is 64.

The square root of 9891765928 is about 99457.3573346889. The cubic root of 9891765928 is about 2146.6337029046.

The spelling of 9891765928 in words is "nine billion, eight hundred ninety-one million, seven hundred sixty-five thousand, nine hundred twenty-eight".