18139394 has 16 divisors (see below), whose sum is σ = 33488448. Its totient is φ = 7175952.

The previous prime is 18139367. The next prime is 18139403. The reversal of 18139394 is 49393181.

It is a happy number.

It is a super-2 number, since 2×18139394² = 658075229374472, which contains 22 as substring.

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, 49652 + ... + 50015.

It is an arithmetic number, because the mean of its divisors is an integer number (2093028).

Almost surely, 2^18139394 is an apocalyptic number.

18139394 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

18139394 is a deficient number, since it is larger than the sum of its proper divisors (15349054).

18139394 is a wasteful number, since it uses less digits than its factorization.

18139394 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 99689.

The product of its digits is 23328, while the sum is 38.

The square root of 18139394 is about 4259.0367455564. The cubic root of 18139394 is about 262.7489109899.

The spelling of 18139394 in words is "eighteen million, one hundred thirty-nine thousand, three hundred ninety-four".