991303864 has 64 divisors (see below), whose sum is σ = 2120048640. Its totient is φ = 431777280.

The previous prime is 991303801. The next prime is 991303867. The reversal of 991303864 is 468303199.

It is a self number, because there is not a number n which added to its sum of digits gives 991303864.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (991303867) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 91857 + ... + 102079.

It is an arithmetic number, because the mean of its divisors is an integer number (33125760).

Almost surely, 2^991303864 is an apocalyptic number.

It is an amenable number.

991303864 is an abundant number, since it is smaller than the sum of its proper divisors (1128744776).

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

991303864 is a wasteful number, since it uses less digits than its factorization.

991303864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10300 (or 10296 counting only the distinct ones).

The product of its (nonzero) digits is 139968, while the sum is 43.

The square root of 991303864 is about 31484.9783865259. The cubic root of 991303864 is about 997.0928446377.

The spelling of 991303864 in words is "nine hundred ninety-one million, three hundred three thousand, eight hundred sixty-four".