18128638 has 8 divisors (see below), whose sum is σ = 29665080. Its totient is φ = 8240280.

The previous prime is 18128609. The next prime is 18128687. The reversal of 18128638 is 83682181.

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

It is a junction number, because it is equal to n+sod(n) for n = 18128597 and 18128606.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 411993 + ... + 412036.

It is an arithmetic number, because the mean of its divisors is an integer number (3708135).

Almost surely, 2^18128638 is an apocalyptic number.

18128638 is a deficient number, since it is larger than the sum of its proper divisors (11536442).

18128638 is a wasteful number, since it uses less digits than its factorization.

18128638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 824042.

The product of its digits is 18432, while the sum is 37.

The square root of 18128638 is about 4257.7738314758. The cubic root of 18128638 is about 262.6969672100.

The spelling of 18128638 in words is "eighteen million, one hundred twenty-eight thousand, six hundred thirty-eight".