638823655678 has 32 divisors (see below), whose sum is σ = 1054483992576. Its totient is φ = 288409160928.

The previous prime is 638823655637. The next prime is 638823655699. The reversal of 638823655678 is 876556328836.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2084325 + ... + 2371087.

It is an arithmetic number, because the mean of its divisors is an integer number (32952624768).

Almost surely, 2^638823655678 is an apocalyptic number.

638823655678 is a deficient number, since it is larger than the sum of its proper divisors (415660336898).

638823655678 is a wasteful number, since it uses less digits than its factorization.

638823655678 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 288648.

The product of its digits is 348364800, while the sum is 67.

The spelling of 638823655678 in words is "six hundred thirty-eight billion, eight hundred twenty-three million, six hundred fifty-five thousand, six hundred seventy-eight".