991575840 has 96 divisors (see below), whose sum is σ = 3131364096. Its totient is φ = 263751680.

The previous prime is 991575833. The next prime is 991575853. The reversal of 991575840 is 48575199.

991575840 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (96).

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

It is a self number, because there is not a number n which added to its sum of digits gives 991575840.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 204484 + ... + 209276.

It is an arithmetic number, because the mean of its divisors is an integer number (32618376).

Almost surely, 2^991575840 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 991575840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1565682048).

991575840 is an abundant number, since it is smaller than the sum of its proper divisors (2139788256).

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

991575840 is a wasteful number, since it uses less digits than its factorization.

991575840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5242 (or 5234 counting only the distinct ones).

The product of its (nonzero) digits is 453600, while the sum is 48.

The square root of 991575840 is about 31489.2972293762. The cubic root of 991575840 is about 997.1840243913.

The spelling of 991575840 in words is "nine hundred ninety-one million, five hundred seventy-five thousand, eight hundred forty".