18189938 has 16 divisors (see below), whose sum is σ = 29460480. Its totient is φ = 8373456.

The previous prime is 18189929. The next prime is 18189947. The reversal of 18189938 is 83998181.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (18189929) and next prime (18189947).

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 18189892 and 18189901.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13583 + ... + 14861.

It is an arithmetic number, because the mean of its divisors is an integer number (1841280).

Almost surely, 2^18189938 is an apocalyptic number.

18189938 is a deficient number, since it is larger than the sum of its proper divisors (11270542).

18189938 is a wasteful number, since it uses less digits than its factorization.

18189938 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1841.

The product of its digits is 124416, while the sum is 47.

The square root of 18189938 is about 4264.9663539118. The cubic root of 18189938 is about 262.9927277551.

The spelling of 18189938 in words is "eighteen million, one hundred eighty-nine thousand, nine hundred thirty-eight".