18138194 has 4 divisors (see below), whose sum is σ = 27207294. Its totient is φ = 9069096.

The previous prime is 18138187. The next prime is 18138203. The reversal of 18138194 is 49183181.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 11812969 + 6325225 = 3437^2 + 2515^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4534547 + ... + 4534550.

Almost surely, 2^18138194 is an apocalyptic number.

18138194 is a deficient number, since it is larger than the sum of its proper divisors (9069100).

18138194 is an equidigital number, since it uses as much as digits as its factorization.

18138194 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9069099.

The product of its digits is 6912, while the sum is 35.

The square root of 18138194 is about 4258.8958663015. The cubic root of 18138194 is about 262.7431168668.

The spelling of 18138194 in words is "eighteen million, one hundred thirty-eight thousand, one hundred ninety-four".