1991566847312 has 40 divisors (see below), whose sum is σ = 4465719532800. Its totient is φ = 842724484992.

The previous prime is 1991566847267. The next prime is 1991566847339. The reversal of 1991566847312 is 2137486651991.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 112534487 + ... + 112552182.

It is an arithmetic number, because the mean of its divisors is an integer number (111642988320).

Almost surely, 2^{1991566847312} is an apocalyptic number.

It is an amenable number.

1991566847312 is an abundant number, since it is smaller than the sum of its proper divisors (2474152685488).

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

1991566847312 is a wasteful number, since it uses less digits than its factorization.

1991566847312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 225086763 (or 225086757 counting only the distinct ones).

The product of its digits is 19595520, while the sum is 62.

The spelling of 1991566847312 in words is "one trillion, nine hundred ninety-one billion, five hundred sixty-six million, eight hundred forty-seven thousand, three hundred twelve".