991047568912 has 10 divisors (see below), whose sum is σ = 1920154664798. Its totient is φ = 495523784448.

The previous prime is 991047568837. The next prime is 991047568913. The reversal of 991047568912 is 219865740199.

991047568912 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 989221203216 + 1826365696 = 994596^2 + 42736^2 .

It is not an unprimeable number, because it can be changed into a prime (991047568913) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30970236513 + ... + 30970236544.

Almost surely, 2^991047568912 is an apocalyptic number.

It is an amenable number.

991047568912 is a deficient number, since it is larger than the sum of its proper divisors (929107095886).

991047568912 is a wasteful number, since it uses less digits than its factorization.

991047568912 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61940473065 (or 61940473059 counting only the distinct ones).

The product of its (nonzero) digits is 9797760, while the sum is 61.

The spelling of 991047568912 in words is "nine hundred ninety-one billion, forty-seven million, five hundred sixty-eight thousand, nine hundred twelve".