638671423108 has 6 divisors (see below), whose sum is σ = 1117674990446. Its totient is φ = 319335711552.

The previous prime is 638671423073. The next prime is 638671423111. The reversal of 638671423108 is 801324176836.

It can be written as a sum of positive squares in only one way, i.e., 472246588804 + 166424834304 = 687202^2 + 407952^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 79833927885 + ... + 79833927892.

Almost surely, 2^638671423108 is an apocalyptic number.

It is an amenable number.

638671423108 is a deficient number, since it is larger than the sum of its proper divisors (479003567338).

638671423108 is a wasteful number, since it uses less digits than its factorization.

638671423108 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 159667855781 (or 159667855779 counting only the distinct ones).

The product of its (nonzero) digits is 1161216, while the sum is 49.

The spelling of 638671423108 in words is "six hundred thirty-eight billion, six hundred seventy-one million, four hundred twenty-three thousand, one hundred eight".