18839639 has 8 divisors (see below), whose sum is σ = 23187360. Its totient is φ = 14906016.

The previous prime is 18839603. The next prime is 18839677. The reversal of 18839639 is 93693881.

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

It is a cyclic number.

It is not a de Polignac number, because 18839639 - 2¹² = 18835543 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 18839593 and 18839602.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18839239) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 103424 + ... + 103605.

It is an arithmetic number, because the mean of its divisors is an integer number (2898420).

Almost surely, 2^18839639 is an apocalyptic number.

18839639 is a deficient number, since it is larger than the sum of its proper divisors (4347721).

18839639 is a wasteful number, since it uses less digits than its factorization.

18839639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 207049.

The product of its digits is 279936, while the sum is 47.

The square root of 18839639 is about 4340.4652976380. The cubic root of 18839639 is about 266.0873278764.

The spelling of 18839639 in words is "eighteen million, eight hundred thirty-nine thousand, six hundred thirty-nine".