638863465138 has 8 divisors (see below), whose sum is σ = 1008731787120. Its totient is φ = 302619536100.

The previous prime is 638863465129. The next prime is 638863465159. The reversal of 638863465138 is 831564368836.

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

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, 8406098188 + ... + 8406098263.

It is an arithmetic number, because the mean of its divisors is an integer number (126091473390).

Almost surely, 2^638863465138 is an apocalyptic number.

638863465138 is a deficient number, since it is larger than the sum of its proper divisors (369868321982).

638863465138 is a wasteful number, since it uses less digits than its factorization.

638863465138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16812196472.

The product of its digits is 59719680, while the sum is 61.

The spelling of 638863465138 in words is "six hundred thirty-eight billion, eight hundred sixty-three million, four hundred sixty-five thousand, one hundred thirty-eight".