18709438 has 16 divisors (see below), whose sum is σ = 30792960. Its totient is φ = 8455000.

The previous prime is 18709417. The next prime is 18709447. The reversal of 18709438 is 83490781.

It is an alternating number because its digits alternate between odd and even.

It is a self number, because there is not a number n which added to its sum of digits gives 18709438.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1563 + ... + 6313.

It is an arithmetic number, because the mean of its divisors is an integer number (1924560).

Almost surely, 2^18709438 is an apocalyptic number.

18709438 is a deficient number, since it is larger than the sum of its proper divisors (12083522).

18709438 is a wasteful number, since it uses less digits than its factorization.

18709438 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4943.

The product of its (nonzero) digits is 48384, while the sum is 40.

The square root of 18709438 is about 4325.4407867869. The cubic root of 18709438 is about 265.4729326229.

The spelling of 18709438 in words is "eighteen million, seven hundred nine thousand, four hundred thirty-eight".