391561807912 has 32 divisors (see below), whose sum is σ = 817962779520. Its totient is φ = 174195773440.

The previous prime is 391561807873. The next prime is 391561807919. The reversal of 391561807912 is 219708165193.

It is a self number, because there is not a number n which added to its sum of digits gives 391561807912.

It is not an unprimeable number, because it can be changed into a prime (391561807919) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 47331673 + ... + 47339944.

It is an arithmetic number, because the mean of its divisors is an integer number (25561336860).

Almost surely, 2^391561807912 is an apocalyptic number.

It is an amenable number.

391561807912 is an abundant number, since it is smaller than the sum of its proper divisors (426400971608).

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

391561807912 is a wasteful number, since it uses less digits than its factorization.

391561807912 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 94671681 (or 94671677 counting only the distinct ones).

The product of its (nonzero) digits is 816480, while the sum is 52.

The spelling of 391561807912 in words is "three hundred ninety-one billion, five hundred sixty-one million, eight hundred seven thousand, nine hundred twelve".