991789828992 has 192 divisors, whose sum is σ = 3092138066160. Its totient is φ = 303913451520.

The previous prime is 991789828987. The next prime is 991789829011. The reversal of 991789828992 is 299828987199.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (192).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 253242 + ... + 1430982.

Almost surely, 2^991789828992 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 991789828992, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1546069033080).

991789828992 is an abundant number, since it is smaller than the sum of its proper divisors (2100348237168).

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

991789828992 is a wasteful number, since it uses less digits than its factorization.

991789828992 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1177821 (or 1177806 counting only the distinct ones).

The product of its digits is 846526464, while the sum is 81.

The spelling of 991789828992 in words is "nine hundred ninety-one billion, seven hundred eighty-nine million, eight hundred twenty-eight thousand, nine hundred ninety-two".