638582648784 has 20 divisors (see below), whose sum is σ = 1649671842816. Its totient is φ = 212860882912.

The previous prime is 638582648771. The next prime is 638582648789. The reversal of 638582648784 is 487846285836.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638582648789) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6651902544 + ... + 6651902639.

Almost surely, 2^638582648784 is an apocalyptic number.

It is an amenable number.

638582648784 is an abundant number, since it is smaller than the sum of its proper divisors (1011089194032).

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

638582648784 is a wasteful number, since it uses less digits than its factorization.

638582648784 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13303805194 (or 13303805188 counting only the distinct ones).

The product of its digits is 495452160, while the sum is 69.

The spelling of 638582648784 in words is "six hundred thirty-eight billion, five hundred eighty-two million, six hundred forty-eight thousand, seven hundred eighty-four".