91815286855679 has 4 divisors (see below), whose sum is σ = 91817383665480. Its totient is φ = 91813190045880.

The previous prime is 91815286855553. The next prime is 91815286855723. The reversal of 91815286855679 is 97655868251819.

It is a happy number.

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 91815286855679 - 2³² = 91810991888383 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 (91815286855079) 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, 1048339217 + ... + 1048426794.

It is an arithmetic number, because the mean of its divisors is an integer number (22954345916370).

Almost surely, 2^{91815286855679} is an apocalyptic number.

91815286855679 is a deficient number, since it is larger than the sum of its proper divisors (2096809801).

91815286855679 is a wasteful number, since it uses less digits than its factorization.

91815286855679 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2096809800.

The product of its digits is 2612736000, while the sum is 80.

The spelling of 91815286855679 in words is "ninety-one trillion, eight hundred fifteen billion, two hundred eighty-six million, eight hundred fifty-five thousand, six hundred seventy-nine".