18837021 has 24 divisors (see below), whose sum is σ = 29475840. Its totient is φ = 10668672.

The previous prime is 18837019. The next prime is 18837041. The reversal of 18837021 is 12073881.

It is a happy number.

It is not a de Polignac number, because 18837021 - 2¹ = 18837019 is a prime.

It is a hoax number, since the sum of its digits (30) coincides with the sum of the digits of its distinct prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 18837021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18837001) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 18165 + ... + 19173.

It is an arithmetic number, because the mean of its divisors is an integer number (1228160).

Almost surely, 2^18837021 is an apocalyptic number.

It is an amenable number.

18837021 is a deficient number, since it is larger than the sum of its proper divisors (10638819).

18837021 is a wasteful number, since it uses less digits than its factorization.

18837021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1153 (or 1146 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 30.

The square root of 18837021 is about 4340.1637065899. The cubic root of 18837021 is about 266.0750019343.

The spelling of 18837021 in words is "eighteen million, eight hundred thirty-seven thousand, twenty-one".