991313328 has 40 divisors (see below), whose sum is σ = 2589678000. Its totient is φ = 326723584.

The previous prime is 991313327. The next prime is 991313329. The reversal of 991313328 is 823313199.

It is an interprime number because it is at equal distance from previous prime (991313327) and next prime (991313329).

It is a super-2 number, since 2×991313328² = 1965404228540871168, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (991313321) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 111753 + ... + 120296.

It is an arithmetic number, because the mean of its divisors is an integer number (64741950).

Almost surely, 2^991313328 is an apocalyptic number.

It is an amenable number.

991313328 is an abundant number, since it is smaller than the sum of its proper divisors (1598364672).

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

991313328 is a wasteful number, since it uses less digits than its factorization.

991313328 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 232149 (or 232143 counting only the distinct ones).

The product of its digits is 34992, while the sum is 39.

The square root of 991313328 is about 31485.1286800610. The cubic root of 991313328 is about 997.0960177168.

The spelling of 991313328 in words is "nine hundred ninety-one million, three hundred thirteen thousand, three hundred twenty-eight".