638587073872 has 80 divisors (see below), whose sum is σ = 1362778401600. Its totient is φ = 287465656320.

The previous prime is 638587073863. The next prime is 638587073903. The reversal of 638587073872 is 278370785836.

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, 47166688 + ... + 47180224.

It is an arithmetic number, because the mean of its divisors is an integer number (17034730020).

Almost surely, 2^638587073872 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 638587073872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (681389200800).

638587073872 is an abundant number, since it is smaller than the sum of its proper divisors (724191327728).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

638587073872 is a wasteful number, since it uses less digits than its factorization.

638587073872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16124 (or 16118 counting only the distinct ones).

The product of its (nonzero) digits is 94832640, while the sum is 64.

The spelling of 638587073872 in words is "six hundred thirty-eight billion, five hundred eighty-seven million, seventy-three thousand, eight hundred seventy-two".