991944784 has 20 divisors (see below), whose sum is σ = 1939857984. Its totient is φ = 491336288.

The previous prime is 991944773. The next prime is 991944847. The reversal of 991944784 is 487449199.

991944784 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 287992 + ... + 291415.

Almost surely, 2^991944784 is an apocalyptic number.

It is an amenable number.

991944784 is a deficient number, since it is larger than the sum of its proper divisors (947913200).

991944784 is a wasteful number, since it uses less digits than its factorization.

991944784 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 579522 (or 579516 counting only the distinct ones).

The product of its digits is 2612736, while the sum is 55.

The square root of 991944784 is about 31495.1549289728. The cubic root of 991944784 is about 997.3076859502.

The spelling of 991944784 in words is "nine hundred ninety-one million, nine hundred forty-four thousand, seven hundred eighty-four".