91757997 has 6 divisors (see below), whose sum is σ = 132539342. Its totient is φ = 61171992.

The previous prime is 91757977. The next prime is 91758083. The reversal of 91757997 is 79975719.

It can be written as a sum of positive squares in only one way, i.e., 84107241 + 7650756 = 9171^2 + 2766^2 .

It is not a de Polignac number, because 91757997 - 2²⁴ = 74980781 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 (91757917) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 5097658 + ... + 5097675.

Almost surely, 2^91757997 is an apocalyptic number.

It is an amenable number.

91757997 is a deficient number, since it is larger than the sum of its proper divisors (40781345).

91757997 is a wasteful number, since it uses less digits than its factorization.

91757997 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10195339 (or 10195336 counting only the distinct ones).

The product of its digits is 1250235, while the sum is 54.

The square root of 91757997 is about 9579.0394612404. The cubic root of 91757997 is about 451.0395669667.

The spelling of 91757997 in words is "ninety-one million, seven hundred fifty-seven thousand, nine hundred ninety-seven".