991055744 has 128 divisors (see below), whose sum is σ = 2391206400. Its totient is φ = 400103424.

The previous prime is 991055707. The next prime is 991055753. The reversal of 991055744 is 447550199.

It is a tau number, because it is divible by the number of its divisors (128).

It is a junction number, because it is equal to n+sod(n) for n = 991055695 and 991055704.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1116869 + ... + 1117755.

It is an arithmetic number, because the mean of its divisors is an integer number (18681300).

Almost surely, 2^991055744 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 991055744, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1195603200).

991055744 is an abundant number, since it is smaller than the sum of its proper divisors (1400150656).

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

991055744 is a wasteful number, since it uses less digits than its factorization.

991055744 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 980 (or 968 counting only the distinct ones).

The product of its (nonzero) digits is 226800, while the sum is 44.

The square root of 991055744 is about 31481.0378482032. The cubic root of 991055744 is about 997.0096480419.

The spelling of 991055744 in words is "nine hundred ninety-one million, fifty-five thousand, seven hundred forty-four".