9991863440 has 160 divisors (see below), whose sum is σ = 25573363200. Its totient is φ = 3608156160.

The previous prime is 9991863437. The next prime is 9991863457. The reversal of 9991863440 is 443681999.

9991863440 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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, 15161831 + ... + 15162489.

It is an arithmetic number, because the mean of its divisors is an integer number (159833520).

Almost surely, 2^9991863440 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 9991863440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (12786681600).

9991863440 is an abundant number, since it is smaller than the sum of its proper divisors (15581499760).

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

9991863440 is a wasteful number, since it uses less digits than its factorization.

9991863440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 985 (or 979 counting only the distinct ones).

The product of its (nonzero) digits is 1679616, while the sum is 53.

The square root of 9991863440 is about 99959.3089211805. The cubic root of 9991863440 is about 2153.8502085769.

The spelling of 9991863440 in words is "nine billion, nine hundred ninety-one million, eight hundred sixty-three thousand, four hundred forty".