91078568689 has 4 divisors (see below), whose sum is σ = 93016410624. Its totient is φ = 89140726756.

The previous prime is 91078568681. The next prime is 91078568723. The reversal of 91078568689 is 98686587019.

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 91078568689 - 2³ = 91078568681 is a prime.

It is a Smith number, since the sum of its digits (67) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (91078568681) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 968920897 + ... + 968920990.

It is an arithmetic number, because the mean of its divisors is an integer number (23254102656).

Almost surely, 2^91078568689 is an apocalyptic number.

It is an amenable number.

91078568689 is a deficient number, since it is larger than the sum of its proper divisors (1937841935).

91078568689 is a wasteful number, since it uses less digits than its factorization.

91078568689 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1937841934.

The product of its (nonzero) digits is 52254720, while the sum is 67.

The spelling of 91078568689 in words is "ninety-one billion, seventy-eight million, five hundred sixty-eight thousand, six hundred eighty-nine".