91330921 has 12 divisors (see below), whose sum is σ = 101812032. Its totient is φ = 81851000.

The previous prime is 91330909. The next prime is 91330931. The reversal of 91330921 is 12903319.

It is not a de Polignac number, because 91330921 - 2¹³ = 91322729 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 91330921.

It is not an unprimeable number, because it can be changed into a prime (91330931) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3276 + ... + 13906.

It is an arithmetic number, because the mean of its divisors is an integer number (8484336).

Almost surely, 2^91330921 is an apocalyptic number.

It is an amenable number.

91330921 is a deficient number, since it is larger than the sum of its proper divisors (10481111).

91330921 is a wasteful number, since it uses less digits than its factorization.

91330921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10724 (or 10713 counting only the distinct ones).

The product of its (nonzero) digits is 1458, while the sum is 28.

The square root of 91330921 is about 9556.7212473735. The cubic root of 91330921 is about 450.3387096024.

The spelling of 91330921 in words is "ninety-one million, three hundred thirty thousand, nine hundred twenty-one".