91291042691 has 4 divisors (see below), whose sum is σ = 91361106192. Its totient is φ = 91220979192.

The previous prime is 91291042669. The next prime is 91291042697. The reversal of 91291042691 is 19624019219.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-91291042691 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (91291042697) 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, 35029796 + ... + 35032401.

It is an arithmetic number, because the mean of its divisors is an integer number (22840276548).

Almost surely, 2^91291042691 is an apocalyptic number.

91291042691 is a deficient number, since it is larger than the sum of its proper divisors (70063501).

91291042691 is a wasteful number, since it uses less digits than its factorization.

91291042691 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70063500.

The product of its (nonzero) digits is 69984, while the sum is 44.

The spelling of 91291042691 in words is "ninety-one billion, two hundred ninety-one million, forty-two thousand, six hundred ninety-one".