91657791 has 8 divisors (see below), whose sum is σ = 135789360. Its totient is φ = 61105176.

The previous prime is 91657789. The next prime is 91657859. The reversal of 91657791 is 19775619.

It is not a de Polignac number, because 91657791 - 2¹ = 91657789 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91657711) 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 7 ways as a sum of consecutive naturals, for example, 1697340 + ... + 1697393.

It is an arithmetic number, because the mean of its divisors is an integer number (16973670).

Almost surely, 2^91657791 is an apocalyptic number.

91657791 is a deficient number, since it is larger than the sum of its proper divisors (44131569).

91657791 is a wasteful number, since it uses less digits than its factorization.

91657791 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3394742 (or 3394736 counting only the distinct ones).

The product of its digits is 119070, while the sum is 45.

The square root of 91657791 is about 9573.8075497683. The cubic root of 91657791 is about 450.8753184906.

The spelling of 91657791 in words is "ninety-one million, six hundred fifty-seven thousand, seven hundred ninety-one".