991785822 has 16 divisors (see below), whose sum is σ = 2025775872. Its totient is φ = 323561240.

The previous prime is 991785793. The next prime is 991785853. The reversal of 991785822 is 228587199.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1758204 + ... + 1758767.

It is an arithmetic number, because the mean of its divisors is an integer number (126610992).

Almost surely, 2^991785822 is an apocalyptic number.

991785822 is an abundant number, since it is smaller than the sum of its proper divisors (1033990050).

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

991785822 is a wasteful number, since it uses less digits than its factorization.

991785822 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3517023.

The product of its digits is 725760, while the sum is 51.

The square root of 991785822 is about 31492.6312333536. The cubic root of 991785822 is about 997.2544092974.

The spelling of 991785822 in words is "nine hundred ninety-one million, seven hundred eighty-five thousand, eight hundred twenty-two".