18689439 has 4 divisors (see below), whose sum is σ = 24919256. Its totient is φ = 12459624.

The previous prime is 18689431. The next prime is 18689441. The reversal of 18689439 is 93498681.

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

It is not a de Polignac number, because 18689439 - 2³ = 18689431 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18689431) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3114904 + ... + 3114909.

It is an arithmetic number, because the mean of its divisors is an integer number (6229814).

Almost surely, 2^18689439 is an apocalyptic number.

18689439 is a deficient number, since it is larger than the sum of its proper divisors (6229817).

18689439 is an equidigital number, since it uses as much as digits as its factorization.

18689439 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6229816.

The product of its digits is 373248, while the sum is 48.

The square root of 18689439 is about 4323.1283811610. The cubic root of 18689439 is about 265.3783086153.

The spelling of 18689439 in words is "eighteen million, six hundred eighty-nine thousand, four hundred thirty-nine".