638611585140 has 48 divisors (see below), whose sum is σ = 1882223622720. Its totient is φ = 161333452800.

The previous prime is 638611585109. The next prime is 638611585187. The reversal of 638611585140 is 41585116836.

It is a self number, because there is not a number n which added to its sum of digits gives 638611585140.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 280091661 + ... + 280093940.

It is an arithmetic number, because the mean of its divisors is an integer number (39212992140).

Almost surely, 2^638611585140 is an apocalyptic number.

638611585140 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

638611585140 is an abundant number, since it is smaller than the sum of its proper divisors (1243612037580).

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

638611585140 is a wasteful number, since it uses less digits than its factorization.

638611585140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 560185632 (or 560185630 counting only the distinct ones).

The product of its (nonzero) digits is 691200, while the sum is 48.

The spelling of 638611585140 in words is "six hundred thirty-eight billion, six hundred eleven million, five hundred eighty-five thousand, one hundred forty".