18113938 has 4 divisors (see below), whose sum is σ = 27170910. Its totient is φ = 9056968.

The previous prime is 18113929. The next prime is 18113939. The reversal of 18113938 is 83931181.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 83931181 = 61 ⋅1375921.

It can be written as a sum of positive squares in only one way, i.e., 18003049 + 110889 = 4243^2 + 333^2 .

It is a super-2 number, since 2×18113938² = 656229499735688, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (18113939) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4528483 + ... + 4528486.

Almost surely, 2^18113938 is an apocalyptic number.

18113938 is a deficient number, since it is larger than the sum of its proper divisors (9056972).

18113938 is an equidigital number, since it uses as much as digits as its factorization.

18113938 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9056971.

The product of its digits is 5184, while the sum is 34.

The square root of 18113938 is about 4256.0472271816. The cubic root of 18113938 is about 262.6259434950.

The spelling of 18113938 in words is "eighteen million, one hundred thirteen thousand, nine hundred thirty-eight".