991984030672896 has 576 divisors, whose sum is σ = 3178159877168640. Its totient is φ = 296676328734720.

The previous prime is 991984030672889. The next prime is 991984030672931. The reversal of 991984030672896 is 698276030489199.

991984030672896 is a `hidden beast` number, since 9 + 9 + 198 + 40 + 306 + 7 + 2 + 89 + 6 = 666.

It is a tau number, because it is divible by the number of its divisors (576).

It is a super-2 number, since 2×991984030672896² (a number of 31 digits) contains 22 as substring.

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 47 ways as a sum of consecutive naturals, for example, 650053380 + ... + 651577596.

It is an arithmetic number, because the mean of its divisors is an integer number (5517638675640).

Almost surely, 2^{991984030672896} is an apocalyptic number.

991984030672896 is a gapful number since it is divisible by the number (96) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 991984030672896, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1589079938584320).

991984030672896 is an abundant number, since it is smaller than the sum of its proper divisors (2186175846495744).

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

991984030672896 is a wasteful number, since it uses less digits than its factorization.

991984030672896 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1524360 (or 1524337 counting only the distinct ones).

The product of its (nonzero) digits is 2539579392, while the sum is 81.

The spelling of 991984030672896 in words is "nine hundred ninety-one trillion, nine hundred eighty-four billion, thirty million, six hundred seventy-two thousand, eight hundred ninety-six".