18638438 has 16 divisors (see below), whose sum is σ = 34409760. Its totient is φ = 7373376.

The previous prime is 18638413. The next prime is 18638467. The reversal of 18638438 is 83483681.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 18638395 and 18638404.

It is a congruent number.

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, 51023 + ... + 51386.

It is an arithmetic number, because the mean of its divisors is an integer number (2150610).

Almost surely, 2^18638438 is an apocalyptic number.

18638438 is a deficient number, since it is larger than the sum of its proper divisors (15771322).

18638438 is a wasteful number, since it uses less digits than its factorization.

18638438 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 102431.

The product of its digits is 110592, while the sum is 41.

The square root of 18638438 is about 4317.2257295629. The cubic root of 18638438 is about 265.1366946364.

It can be divided in two parts, 1863 and 8438, that added together give a palindrome (10301).

The spelling of 18638438 in words is "eighteen million, six hundred thirty-eight thousand, four hundred thirty-eight".