991814743040 has 264 divisors, whose sum is σ = 2635471756512. Its totient is φ = 355186360320.

The previous prime is 991814743037. The next prime is 991814743057. The reversal of 991814743040 is 40347418199.

It is a self number, because there is not a number n which added to its sum of digits gives 991814743040.

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 23 ways as a sum of consecutive naturals, for example, 252818519 + ... + 252822441.

Almost surely, 2^991814743040 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 991814743040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1317735878256).

991814743040 is an abundant number, since it is smaller than the sum of its proper divisors (1643657013472).

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

991814743040 is a wasteful number, since it uses less digits than its factorization.

991814743040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4093 (or 4008 counting only the distinct ones).

The product of its (nonzero) digits is 870912, while the sum is 50.

The spelling of 991814743040 in words is "nine hundred ninety-one billion, eight hundred fourteen million, seven hundred forty-three thousand, forty".