91040839 has 4 divisors (see below), whose sum is σ = 91757824. Its totient is φ = 90323856.

The previous prime is 91040827. The next prime is 91040861. The reversal of 91040839 is 93804019.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-91040839 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91040819) 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, 358302 + ... + 358555.

It is an arithmetic number, because the mean of its divisors is an integer number (22939456).

Almost surely, 2^91040839 is an apocalyptic number.

91040839 is a deficient number, since it is larger than the sum of its proper divisors (716985).

91040839 is a wasteful number, since it uses less digits than its factorization.

91040839 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 716984.

The product of its (nonzero) digits is 7776, while the sum is 34.

The square root of 91040839 is about 9541.5323192871. The cubic root of 91040839 is about 449.8614207028.

The spelling of 91040839 in words is "ninety-one million, forty thousand, eight hundred thirty-nine".