91238057 has 6 divisors (see below), whose sum is σ = 96293178. Its totient is φ = 86435712.

The previous prime is 91238051. The next prime is 91238087. The reversal of 91238057 is 75083219.

It can be written as a sum of positive squares in only one way, i.e., 55190041 + 36048016 = 7429^2 + 6004^2 .

It is not a de Polignac number, because 91238057 - 2⁸ = 91237801 is a prime.

It is not an unprimeable number, because it can be changed into a prime (91238051) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 126008 + ... + 126729.

It is an arithmetic number, because the mean of its divisors is an integer number (16048863).

Almost surely, 2^91238057 is an apocalyptic number.

It is an amenable number.

91238057 is a deficient number, since it is larger than the sum of its proper divisors (5055121).

91238057 is a wasteful number, since it uses less digits than its factorization.

91238057 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 252775 (or 252756 counting only the distinct ones).

The product of its (nonzero) digits is 15120, while the sum is 35.

The square root of 91238057 is about 9551.8614416249. The cubic root of 91238057 is about 450.1860251462.

The spelling of 91238057 in words is "ninety-one million, two hundred thirty-eight thousand, fifty-seven".