991000012 has 12 divisors (see below), whose sum is σ = 1776549096. Its totient is φ = 483414560.

The previous prime is 990999949. The next prime is 991000051. The reversal of 991000012 is 210000199.

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, 3021178 + ... + 3021505.

It is an arithmetic number, because the mean of its divisors is an integer number (148045758).

Almost surely, 2^991000012 is an apocalyptic number.

It is an amenable number.

991000012 is a deficient number, since it is larger than the sum of its proper divisors (785549084).

991000012 is a wasteful number, since it uses less digits than its factorization.

991000012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6042728 (or 6042726 counting only the distinct ones).

The product of its (nonzero) digits is 162, while the sum is 22.

The square root of 991000012 is about 31480.1526679907. The cubic root of 991000012 is about 996.9909587524.

The spelling of 991000012 in words is "nine hundred ninety-one million, twelve", and thus it is an aban number.