18738321 has 24 divisors (see below), whose sum is σ = 29600064. Its totient is φ = 10328640.

The previous prime is 18738311. The next prime is 18738323. The reversal of 18738321 is 12383781.

It is not a de Polignac number, because 18738321 - 2¹⁰ = 18737297 is a prime.

It is a super-2 number, since 2×18738321² = 702249347798082, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (18738323) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 17131 + ... + 18191.

It is an arithmetic number, because the mean of its divisors is an integer number (1233336).

Almost surely, 2^18738321 is an apocalyptic number.

It is an amenable number.

18738321 is a deficient number, since it is larger than the sum of its proper divisors (10861743).

18738321 is a wasteful number, since it uses less digits than its factorization.

18738321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1129 (or 1100 counting only the distinct ones).

The product of its digits is 8064, while the sum is 33.

The square root of 18738321 is about 4328.7782340979. The cubic root of 18738321 is about 265.6094717751.

The spelling of 18738321 in words is "eighteen million, seven hundred thirty-eight thousand, three hundred twenty-one".