7891091 has 4 divisors (see below), whose sum is σ = 8498112. Its totient is φ = 7284072.

The previous prime is 7891069. The next prime is 7891123. The reversal of 7891091 is 1901987.

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 7891091 - 2¹⁰ = 7890067 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (7891031) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 303491 + ... + 303516.

It is an arithmetic number, because the mean of its divisors is an integer number (2124528).

Almost surely, 2^7891091 is an apocalyptic number.

7891091 is a deficient number, since it is larger than the sum of its proper divisors (607021).

7891091 is a wasteful number, since it uses less digits than its factorization.

7891091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 607020.

The product of its (nonzero) digits is 4536, while the sum is 35.

The square root of 7891091 is about 2809.1085774672. The cubic root of 7891091 is about 199.0882751041.

The spelling of 7891091 in words is "seven million, eight hundred ninety-one thousand, ninety-one".