91581705077 has 4 divisors (see below), whose sum is σ = 91597320576. Its totient is φ = 91566089580.

The previous prime is 91581705073. The next prime is 91581705109. The reversal of 91581705077 is 77050718519.

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 91581705077 - 2² = 91581705073 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 (91581705073) 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, 7798949 + ... + 7810682.

It is an arithmetic number, because the mean of its divisors is an integer number (22899330144).

Almost surely, 2^91581705077 is an apocalyptic number.

It is an amenable number.

91581705077 is a deficient number, since it is larger than the sum of its proper divisors (15615499).

91581705077 is a wasteful number, since it uses less digits than its factorization.

91581705077 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15615498.

The product of its (nonzero) digits is 617400, while the sum is 50.

The spelling of 91581705077 in words is "ninety-one billion, five hundred eighty-one million, seven hundred five thousand, seventy-seven".