8320991 has 16 divisors (see below), whose sum is σ = 9891840. Its totient is φ = 6851520.

The previous prime is 8320943. The next prime is 8321003. The reversal of 8320991 is 1990238.

It is a cyclic number.

It is not a de Polignac number, because 8320991 - 2¹⁴ = 8304607 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8320591) 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, 22490 + ... + 22856.

It is an arithmetic number, because the mean of its divisors is an integer number (618240).

Almost surely, 2^8320991 is an apocalyptic number.

8320991 is a deficient number, since it is larger than the sum of its proper divisors (1570849).

8320991 is a wasteful number, since it uses less digits than its factorization.

8320991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 494.

The product of its (nonzero) digits is 3888, while the sum is 32.

The square root of 8320991 is about 2884.6127989732. The cubic root of 8320991 is about 202.6399256447.

The spelling of 8320991 in words is "eight million, three hundred twenty thousand, nine hundred ninety-one".