991345824 has 192 divisors, whose sum is σ = 3478809600. Its totient is φ = 268303104.

The previous prime is 991345819. The next prime is 991345829. The reversal of 991345824 is 428543199.

991345824 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (991345819) and next prime (991345829).

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 991345824.

It is not an unprimeable number, because it can be changed into a prime (991345829) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 110599 + ... + 119225.

It is an arithmetic number, because the mean of its divisors is an integer number (18118800).

Almost surely, 2^991345824 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 991345824, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1739404800).

991345824 is an abundant number, since it is smaller than the sum of its proper divisors (2487463776).

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

991345824 is a wasteful number, since it uses less digits than its factorization.

991345824 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8672 (or 8658 counting only the distinct ones).

The product of its digits is 311040, while the sum is 45.

The square root of 991345824 is about 31485.6447289872. The cubic root of 991345824 is about 997.1069127847.

The spelling of 991345824 in words is "nine hundred ninety-one million, three hundred forty-five thousand, eight hundred twenty-four".