18685939838 has 4 divisors (see below), whose sum is σ = 28028909760. Its totient is φ = 9342969918.

The previous prime is 18685939829. The next prime is 18685939873. The reversal of 18685939838 is 83893958681.

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

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 as a sum of consecutive naturals, namely, 4671484958 + ... + 4671484961.

It is an arithmetic number, because the mean of its divisors is an integer number (7007227440).

Almost surely, 2^18685939838 is an apocalyptic number.

18685939838 is a deficient number, since it is larger than the sum of its proper divisors (9342969922).

18685939838 is an equidigital number, since it uses as much as digits as its factorization.

18685939838 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9342969921.

The product of its digits is 89579520, while the sum is 68.

The spelling of 18685939838 in words is "eighteen billion, six hundred eighty-five million, nine hundred thirty-nine thousand, eight hundred thirty-eight".