991012 has 24 divisors (see below), whose sum is σ = 1919232. Its totient is φ = 444000.

The previous prime is 991009. The next prime is 991027. The reversal of 991012 is 210199.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4333 + ... + 4555.

It is an arithmetic number, because the mean of its divisors is an integer number (79968).

2⁹⁹¹⁰¹² is an apocalyptic number.

It is an amenable number.

991012 is a deficient number, since it is larger than the sum of its proper divisors (928220).

991012 is a wasteful number, since it uses less digits than its factorization.

991012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 339 (or 337 counting only the distinct ones).

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

The square root of 991012 is about 995.4958563450. The cubic root of 991012 is about 99.6994978893.

It can be divided in two parts, 99 and 1012, that added together give a palindrome (1111).

The spelling of 991012 in words is "nine hundred ninety-one thousand, twelve".