8243991 has 32 divisors (see below), whose sum is σ = 14238720. Its totient is φ = 4616352.

The previous prime is 8243971. The next prime is 8244001. The reversal of 8243991 is 1993428.

It is not a de Polignac number, because 8243991 - 2⁶ = 8243927 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8243971) 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, 9606 + ... + 10428.

It is an arithmetic number, because the mean of its divisors is an integer number (444960).

Almost surely, 2^8243991 is an apocalyptic number.

8243991 is a deficient number, since it is larger than the sum of its proper divisors (5994729).

8243991 is a wasteful number, since it uses less digits than its factorization.

8243991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 892 (or 886 counting only the distinct ones).

The product of its digits is 15552, while the sum is 36.

The square root of 8243991 is about 2871.2351000919. The cubic root of 8243991 is about 202.0129309109.

The spelling of 8243991 in words is "eight million, two hundred forty-three thousand, nine hundred ninety-one".