991565912 has 48 divisors (see below), whose sum is σ = 1935919440. Its totient is φ = 476104832.

The previous prime is 991565879. The next prime is 991565917. The reversal of 991565912 is 219565199.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (991565917) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 1971053 + ... + 1971555.

It is an arithmetic number, because the mean of its divisors is an integer number (40331655).

Almost surely, 2^991565912 is an apocalyptic number.

It is an amenable number.

991565912 is a deficient number, since it is larger than the sum of its proper divisors (944353528).

991565912 is a wasteful number, since it uses less digits than its factorization.

991565912 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 860 (or 827 counting only the distinct ones).

The product of its digits is 218700, while the sum is 47.

The square root of 991565912 is about 31489.1395881183. The cubic root of 991565912 is about 997.1806963299.

The spelling of 991565912 in words is "nine hundred ninety-one million, five hundred sixty-five thousand, nine hundred twelve".