9918021 has 8 divisors (see below), whose sum is σ = 14001984. Its totient is φ = 6223040.

The previous prime is 9918017. The next prime is 9918059. The reversal of 9918021 is 1208199.

9918021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 9918021 - 2² = 9918017 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 9918021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9918091) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 97185 + ... + 97286.

It is an arithmetic number, because the mean of its divisors is an integer number (1750248).

Almost surely, 2^9918021 is an apocalyptic number.

It is an amenable number.

9918021 is a deficient number, since it is larger than the sum of its proper divisors (4083963).

9918021 is a wasteful number, since it uses less digits than its factorization.

9918021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 194491.

The product of its (nonzero) digits is 1296, while the sum is 30.

The square root of 9918021 is about 3149.2889673703. The cubic root of 9918021 is about 214.8531248533.

The spelling of 9918021 in words is "nine million, nine hundred eighteen thousand, twenty-one".