8391091 has 4 divisors (see below), whose sum is σ = 8418384. Its totient is φ = 8363800.

The previous prime is 8391083. The next prime is 8391109. The reversal of 8391091 is 1901938.

8391091 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 8391091 - 2³ = 8391083 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (8391001) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13180 + ... + 13801.

It is an arithmetic number, because the mean of its divisors is an integer number (2104596).

Almost surely, 2^8391091 is an apocalyptic number.

8391091 is a deficient number, since it is larger than the sum of its proper divisors (27293).

8391091 is a wasteful number, since it uses less digits than its factorization.

8391091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27292.

The product of its (nonzero) digits is 1944, while the sum is 31.

The square root of 8391091 is about 2896.7379929845. The cubic root of 8391091 is about 203.2073802655.

The spelling of 8391091 in words is "eight million, three hundred ninety-one thousand, ninety-one".