91531928 has 16 divisors (see below), whose sum is σ = 173796000. Its totient is φ = 45186336.

The previous prime is 91531897. The next prime is 91531963. The reversal of 91531928 is 82913519.

It is a junction number, because it is equal to n+sod(n) for n = 91531891 and 91531900.

It is a congruent number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 71783 + ... + 73046.

It is an arithmetic number, because the mean of its divisors is an integer number (10862250).

Almost surely, 2^91531928 is an apocalyptic number.

It is an amenable number.

91531928 is a deficient number, since it is larger than the sum of its proper divisors (82264072).

91531928 is a wasteful number, since it uses less digits than its factorization.

91531928 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 144914 (or 144910 counting only the distinct ones).

The product of its digits is 19440, while the sum is 38.

The square root of 91531928 is about 9567.2319925880. The cubic root of 91531928 is about 450.6688457154.

The spelling of 91531928 in words is "ninety-one million, five hundred thirty-one thousand, nine hundred twenty-eight".