991837996032 has 352 divisors, whose sum is σ = 2952443450880. Its totient is φ = 293926993920.

The previous prime is 991837995971. The next prime is 991837996069. The reversal of 991837996032 is 230699738199.

It is a happy number.

It is a super-2 number, since 2×991837996032² (a number of 25 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 626555113 + ... + 626556695.

It is an arithmetic number, because the mean of its divisors is an integer number (8387623440).

Almost surely, 2^991837996032 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 991837996032, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1476221725440).

991837996032 is an abundant number, since it is smaller than the sum of its proper divisors (1960605454848).

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

991837996032 is a wasteful number, since it uses less digits than its factorization.

991837996032 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2189 (or 2171 counting only the distinct ones).

The product of its (nonzero) digits is 39680928, while the sum is 66.

The spelling of 991837996032 in words is "nine hundred ninety-one billion, eight hundred thirty-seven million, nine hundred ninety-six thousand, thirty-two".