18438642 has 24 divisors (see below), whose sum is σ = 42301116. Its totient is φ = 5784576.

The previous prime is 18438619. The next prime is 18438649. The reversal of 18438642 is 24683481.

18438642 is a `hidden beast` number, since 1 + 8 + 4 + 3 + 8 + 642 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 16719921 + 1718721 = 4089^2 + 1311^2 .

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 18438597 and 18438606.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18438649) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 29823 + ... + 30434.

Almost surely, 2^18438642 is an apocalyptic number.

18438642 is an abundant number, since it is smaller than the sum of its proper divisors (23862474).

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

18438642 is a wasteful number, since it uses less digits than its factorization.

18438642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 60282 (or 60279 counting only the distinct ones).

The product of its digits is 36864, while the sum is 36.

The square root of 18438642 is about 4294.0239868915. The cubic root of 18438642 is about 264.1859055582.

The spelling of 18438642 in words is "eighteen million, four hundred thirty-eight thousand, six hundred forty-two".