638421541108 has 24 divisors (see below), whose sum is σ = 1203288705248. Its totient is φ = 294629243616.

The previous prime is 638421541103. The next prime is 638421541111. The reversal of 638421541108 is 801145124836.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638421541103) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 22435 + ... + 1130197.

Almost surely, 2^638421541108 is an apocalyptic number.

It is an amenable number.

638421541108 is a deficient number, since it is larger than the sum of its proper divisors (564867164140).

638421541108 is a wasteful number, since it uses less digits than its factorization.

638421541108 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1118863 (or 1118861 counting only the distinct ones).

The product of its (nonzero) digits is 184320, while the sum is 43.

The spelling of 638421541108 in words is "six hundred thirty-eight billion, four hundred twenty-one million, five hundred forty-one thousand, one hundred eight".