91117445809 has 4 divisors (see below), whose sum is σ = 98126480116. Its totient is φ = 84108411504.

The previous prime is 91117445803. The next prime is 91117445831. The reversal of 91117445809 is 90854471119.

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

It can be written as a sum of positive squares in 2 ways, for example, as 45888066225 + 45229379584 = 214215^2 + 212672^2 .

It is not a de Polignac number, because 91117445809 - 2¹³ = 91117437617 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (91117445803) 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, 3504517134 + ... + 3504517159.

It is an arithmetic number, because the mean of its divisors is an integer number (24531620029).

Almost surely, 2^91117445809 is an apocalyptic number.

It is an amenable number.

91117445809 is a deficient number, since it is larger than the sum of its proper divisors (7009034307).

91117445809 is a wasteful number, since it uses less digits than its factorization.

91117445809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7009034306.

The product of its (nonzero) digits is 362880, while the sum is 49.

The spelling of 91117445809 in words is "ninety-one billion, one hundred seventeen million, four hundred forty-five thousand, eight hundred nine".