991581076 has 12 divisors (see below), whose sum is σ = 1739187072. Its totient is φ = 494670488.

The previous prime is 991581067. The next prime is 991581077. The reversal of 991581076 is 670185199.

It is a happy number.

991581076 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (991581077) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 278020 + ... + 281563.

It is an arithmetic number, because the mean of its divisors is an integer number (144932256).

Almost surely, 2^991581076 is an apocalyptic number.

It is an amenable number.

991581076 is a deficient number, since it is larger than the sum of its proper divisors (747605996).

991581076 is a wasteful number, since it uses less digits than its factorization.

991581076 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 560030 (or 560028 counting only the distinct ones).

The product of its (nonzero) digits is 136080, while the sum is 46.

The square root of 991581076 is about 31489.3803686259. The cubic root of 991581076 is about 997.1857795929.

The spelling of 991581076 in words is "nine hundred ninety-one million, five hundred eighty-one thousand, seventy-six".