18189394 has 4 divisors (see below), whose sum is σ = 27284094. Its totient is φ = 9094696.

The previous prime is 18189377. The next prime is 18189397. The reversal of 18189394 is 49398181.

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., 13068225 + 5121169 = 3615^2 + 2263^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 18189394.

It is not an unprimeable number, because it can be changed into a prime (18189397) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4547347 + ... + 4547350.

Almost surely, 2^18189394 is an apocalyptic number.

18189394 is a deficient number, since it is larger than the sum of its proper divisors (9094700).

18189394 is an equidigital number, since it uses as much as digits as its factorization.

18189394 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9094699.

The product of its digits is 62208, while the sum is 43.

The square root of 18189394 is about 4264.9025780198. The cubic root of 18189394 is about 262.9901059857.

The spelling of 18189394 in words is "eighteen million, one hundred eighty-nine thousand, three hundred ninety-four".