18138922 has 4 divisors (see below), whose sum is σ = 27208386. Its totient is φ = 9069460.

The previous prime is 18138919. The next prime is 18138931. The reversal of 18138922 is 22983181.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 22983181 = 13 ⋅1767937.

It can be written as a sum of positive squares in only one way, i.e., 13682601 + 4456321 = 3699^2 + 2111^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4534729 + ... + 4534732.

Almost surely, 2^18138922 is an apocalyptic number.

18138922 is a deficient number, since it is larger than the sum of its proper divisors (9069464).

18138922 is an equidigital number, since it uses as much as digits as its factorization.

18138922 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9069463.

The product of its digits is 6912, while the sum is 34.

The square root of 18138922 is about 4258.9813336055. The cubic root of 18138922 is about 262.7466319986.

The spelling of 18138922 in words is "eighteen million, one hundred thirty-eight thousand, nine hundred twenty-two".