18609638 has 4 divisors (see below), whose sum is σ = 27914460. Its totient is φ = 9304818.

The previous prime is 18609637. The next prime is 18609673. The reversal of 18609638 is 83690681.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 18609595 and 18609604.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18609637) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4652408 + ... + 4652411.

It is an arithmetic number, because the mean of its divisors is an integer number (6978615).

Almost surely, 2^18609638 is an apocalyptic number.

18609638 is a deficient number, since it is larger than the sum of its proper divisors (9304822).

18609638 is an equidigital number, since it uses as much as digits as its factorization.

18609638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9304821.

The product of its (nonzero) digits is 62208, while the sum is 41.

The square root of 18609638 is about 4313.8889647278. Note that the first 3 decimals coincide. The cubic root of 18609638 is about 265.0000617064. Note that the first 4 decimals are identical.

The spelling of 18609638 in words is "eighteen million, six hundred nine thousand, six hundred thirty-eight".