18381894 has 16 divisors (see below), whose sum is σ = 36861168. Its totient is φ = 6111072.

The previous prime is 18381893. The next prime is 18381901. The reversal of 18381894 is 49818381.

It is a super-3 number, since 3×18381894³ (a number of 23 digits) contains 333 as substring.

It is an alternating number because its digits alternate between odd and even.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18381893) by changing a digit.

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 in 7 ways as a sum of consecutive naturals, for example, 1477 + ... + 6240.

It is an arithmetic number, because the mean of its divisors is an integer number (2303823).

Almost surely, 2^18381894 is an apocalyptic number.

18381894 is an abundant number, since it is smaller than the sum of its proper divisors (18479274).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18381894 is a wasteful number, since it uses less digits than its factorization.

18381894 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8119.

The product of its digits is 55296, while the sum is 42.

The square root of 18381894 is about 4287.4111069502. The cubic root of 18381894 is about 263.9146016254.

The spelling of 18381894 in words is "eighteen million, three hundred eighty-one thousand, eight hundred ninety-four".