91371577879 has 4 divisors (see below), whose sum is σ = 91414822576. Its totient is φ = 91328333184.

The previous prime is 91371577763. The next prime is 91371577889. The reversal of 91371577879 is 97877517319.

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 91371577879 - 2¹³ = 91371569687 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 91371577879.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91371577889) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21619179 + ... + 21623404.

It is an arithmetic number, because the mean of its divisors is an integer number (22853705644).

Almost surely, 2^91371577879 is an apocalyptic number.

91371577879 is a deficient number, since it is larger than the sum of its proper divisors (43244697).

91371577879 is a wasteful number, since it uses less digits than its factorization.

91371577879 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43244696.

The product of its digits is 23337720, while the sum is 64.

The spelling of 91371577879 in words is "ninety-one billion, three hundred seventy-one million, five hundred seventy-seven thousand, eight hundred seventy-nine".