91580813 has 4 divisors (see below), whose sum is σ = 91830720. Its totient is φ = 91330908.

The previous prime is 91580791. The next prime is 91580833. The reversal of 91580813 is 31808519.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 91580813 - 2²⁰ = 90532237 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 (91580833) 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, 124403 + ... + 125136.

It is an arithmetic number, because the mean of its divisors is an integer number (22957680).

Almost surely, 2^91580813 is an apocalyptic number.

It is an amenable number.

91580813 is a deficient number, since it is larger than the sum of its proper divisors (249907).

91580813 is a wasteful number, since it uses less digits than its factorization.

91580813 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 249906.

The product of its (nonzero) digits is 8640, while the sum is 35.

The square root of 91580813 is about 9569.7864657473. The cubic root of 91580813 is about 450.7490618982.

The spelling of 91580813 in words is "ninety-one million, five hundred eighty thousand, eight hundred thirteen".