18431138 has 8 divisors (see below), whose sum is σ = 30160080. Its totient is φ = 8377780.

The previous prime is 18431131. The next prime is 18431167. The reversal of 18431138 is 83113481.

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

It is a self number, because there is not a number n which added to its sum of digits gives 18431138.

It is not an unprimeable number, because it can be changed into a prime (18431131) 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 3 ways as a sum of consecutive naturals, for example, 418868 + ... + 418911.

It is an arithmetic number, because the mean of its divisors is an integer number (3770010).

Almost surely, 2^18431138 is an apocalyptic number.

18431138 is a deficient number, since it is larger than the sum of its proper divisors (11728942).

18431138 is a wasteful number, since it uses less digits than its factorization.

18431138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 837792.

The product of its digits is 2304, while the sum is 29.

The square root of 18431138 is about 4293.1501254906. The cubic root of 18431138 is about 264.1500619925.

The spelling of 18431138 in words is "eighteen million, four hundred thirty-one thousand, one hundred thirty-eight".