928191091 has 4 divisors (see below), whose sum is σ = 930506184. Its totient is φ = 925876000.

The previous prime is 928191083. The next prime is 928191101. The reversal of 928191091 is 190191829.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 928191091 - 2³ = 928191083 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (928191001) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1156945 + ... + 1157746.

It is an arithmetic number, because the mean of its divisors is an integer number (232626546).

Almost surely, 2^928191091 is an apocalyptic number.

928191091 is a deficient number, since it is larger than the sum of its proper divisors (2315093).

928191091 is a wasteful number, since it uses less digits than its factorization.

928191091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2315092.

The product of its (nonzero) digits is 11664, while the sum is 40.

The square root of 928191091 is about 30466.2286967061. The cubic root of 928191091 is about 975.4667380945.

The spelling of 928191091 in words is "nine hundred twenty-eight million, one hundred ninety-one thousand, ninety-one".