18538389 has 10 divisors (see below), whose sum is σ = 27693270. Its totient is φ = 12358872.

The previous prime is 18538367. The next prime is 18538427. The reversal of 18538389 is 98383581.

It can be written as a sum of positive squares in only one way, i.e., 13950225 + 4588164 = 3735^2 + 2142^2 .

It is not a de Polignac number, because 18538389 - 2⁹ = 18537877 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18538189) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 114354 + ... + 114515.

It is an arithmetic number, because the mean of its divisors is an integer number (2769327).

Almost surely, 2^18538389 is an apocalyptic number.

It is an amenable number.

18538389 is a deficient number, since it is larger than the sum of its proper divisors (9154881).

18538389 is an equidigital number, since it uses as much as digits as its factorization.

18538389 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 228881 (or 228872 counting only the distinct ones).

The product of its digits is 207360, while the sum is 45.

The square root of 18538389 is about 4305.6229514438. The cubic root of 18538389 is about 264.6614354393.

The spelling of 18538389 in words is "eighteen million, five hundred thirty-eight thousand, three hundred eighty-nine".