638844663118 has 8 divisors (see below), whose sum is σ = 1008702099720. Its totient is φ = 302610629880.

The previous prime is 638844663103. The next prime is 638844663167. The reversal of 638844663118 is 811366448836.

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8405850793 + ... + 8405850868.

It is an arithmetic number, because the mean of its divisors is an integer number (126087762465).

Almost surely, 2^638844663118 is an apocalyptic number.

638844663118 is a deficient number, since it is larger than the sum of its proper divisors (369857436602).

638844663118 is a wasteful number, since it uses less digits than its factorization.

638844663118 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16811701682.

The product of its digits is 15925248, while the sum is 58.

The spelling of 638844663118 in words is "six hundred thirty-eight billion, eight hundred forty-four million, six hundred sixty-three thousand, one hundred eighteen".