9891918 has 12 divisors (see below), whose sum is σ = 21432528. Its totient is φ = 3297300.

The previous prime is 9891899. The next prime is 9891923. The reversal of 9891918 is 8191989.

9891918 is digitally balanced in base 2 and base 4, because in such bases it contains all the possibile digits an equal number of times.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 274758 + ... + 274793.

It is an arithmetic number, because the mean of its divisors is an integer number (1786044).

Almost surely, 2^9891918 is an apocalyptic number.

9891918 is an abundant number, since it is smaller than the sum of its proper divisors (11540610).

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

9891918 is a wasteful number, since it uses less digits than its factorization.

9891918 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 549559 (or 549556 counting only the distinct ones).

The product of its digits is 46656, while the sum is 45.

The square root of 9891918 is about 3145.1419681789. The cubic root of 9891918 is about 214.6644703340.

The spelling of 9891918 in words is "nine million, eight hundred ninety-one thousand, nine hundred eighteen".