638824266388 has 96 divisors (see below), whose sum is σ = 1428412237056. Its totient is φ = 242716800000.

The previous prime is 638824266373. The next prime is 638824266439. The reversal of 638824266388 is 883662428836.

638824266388 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 33088338 + ... + 33107638.

It is an arithmetic number, because the mean of its divisors is an integer number (14879294136).

Almost surely, 2^638824266388 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 638824266388, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (714206118528).

638824266388 is an abundant number, since it is smaller than the sum of its proper divisors (789587970668).

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

638824266388 is a wasteful number, since it uses less digits than its factorization.

638824266388 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21985 (or 21983 counting only the distinct ones).

The product of its digits is 127401984, while the sum is 64.

The spelling of 638824266388 in words is "six hundred thirty-eight billion, eight hundred twenty-four million, two hundred sixty-six thousand, three hundred eighty-eight".