18634638 has 32 divisors (see below), whose sum is σ = 40828032. Its totient is φ = 5623200.

The previous prime is 18634633. The next prime is 18634639. The reversal of 18634638 is 83643681.

It is a junction number, because it is equal to n+sod(n) for n = 18634596 and 18634605.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18634631) 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 15 ways as a sum of consecutive naturals, for example, 21420 + ... + 22272.

It is an arithmetic number, because the mean of its divisors is an integer number (1275876).

Almost surely, 2^18634638 is an apocalyptic number.

18634638 is an abundant number, since it is smaller than the sum of its proper divisors (22193394).

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

18634638 is a wasteful number, since it uses less digits than its factorization.

18634638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1200.

The product of its digits is 82944, while the sum is 39.

The square root of 18634638 is about 4316.7856096869. The cubic root of 18634638 is about 265.1186747445.

The spelling of 18634638 in words is "eighteen million, six hundred thirty-four thousand, six hundred thirty-eight".