991900944 has 80 divisors (see below), whose sum is σ = 2970940800. Its totient is φ = 316255104.

The previous prime is 991900939. The next prime is 991900993. The reversal of 991900944 is 449009199.

991900944 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×991900944² = 1967734965416182272, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 991900944.

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, 39979 + ... + 59850.

It is an arithmetic number, because the mean of its divisors is an integer number (37136760).

Almost surely, 2^991900944 is an apocalyptic number.

It is an amenable number.

991900944 is an abundant number, since it is smaller than the sum of its proper divisors (1979039856).

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

991900944 is a wasteful number, since it uses less digits than its factorization.

991900944 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 99869 (or 99857 counting only the distinct ones).

The product of its (nonzero) digits is 104976, while the sum is 45.

The square root of 991900944 is about 31494.4589412169. The cubic root of 991900944 is about 997.2929933941.

The spelling of 991900944 in words is "nine hundred ninety-one million, nine hundred thousand, nine hundred forty-four".