18163994 has 8 divisors (see below), whose sum is σ = 27429300. Its totient is φ = 9020896.

The previous prime is 18163987. The next prime is 18164011. The reversal of 18163994 is 49936181.

It can be written as a sum of positive squares in 2 ways, for example, as 15484225 + 2679769 = 3935^2 + 1637^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 30179 + ... + 30774.

Almost surely, 2^18163994 is an apocalyptic number.

18163994 is a deficient number, since it is larger than the sum of its proper divisors (9265306).

18163994 is a wasteful number, since it uses less digits than its factorization.

18163994 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61104.

The product of its digits is 46656, while the sum is 41.

The square root of 18163994 is about 4261.9237440386. The cubic root of 18163994 is about 262.8676342412.

The spelling of 18163994 in words is "eighteen million, one hundred sixty-three thousand, nine hundred ninety-four".