91381928 has 32 divisors (see below), whose sum is σ = 187319520. Its totient is φ = 41448000.

The previous prime is 91381891. The next prime is 91381943. The reversal of 91381928 is 82918319.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 57383 + ... + 58953.

It is an arithmetic number, because the mean of its divisors is an integer number (5853735).

Almost surely, 2^91381928 is an apocalyptic number.

It is an amenable number.

91381928 is an abundant number, since it is smaller than the sum of its proper divisors (95937592).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

91381928 is a wasteful number, since it uses less digits than its factorization.

91381928 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2249 (or 2245 counting only the distinct ones).

The product of its digits is 31104, while the sum is 41.

The square root of 91381928 is about 9559.3895202570. The cubic root of 91381928 is about 450.4225298881.

The spelling of 91381928 in words is "ninety-one million, three hundred eighty-one thousand, nine hundred twenty-eight".