91573340879 has 4 divisors (see below), whose sum is σ = 93806837040. Its totient is φ = 89339844720.

The previous prime is 91573340839. The next prime is 91573340941. The reversal of 91573340879 is 97804337519.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 97804337519 = 7 ⋅13972048217.

It is a cyclic number.

It is not a de Polignac number, because 91573340879 - 2²⁸ = 91304905423 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 (91573340839) 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, 1116748019 + ... + 1116748100.

It is an arithmetic number, because the mean of its divisors is an integer number (23451709260).

Almost surely, 2^91573340879 is an apocalyptic number.

91573340879 is a deficient number, since it is larger than the sum of its proper divisors (2233496161).

91573340879 is a wasteful number, since it uses less digits than its factorization.

91573340879 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2233496160.

The product of its (nonzero) digits is 5715360, while the sum is 56.

The spelling of 91573340879 in words is "ninety-one billion, five hundred seventy-three million, three hundred forty thousand, eight hundred seventy-nine".