638011637432 has 64 divisors (see below), whose sum is σ = 1297763396160. Its totient is φ = 292305024000.

The previous prime is 638011637411. The next prime is 638011637437. The reversal of 638011637432 is 234736110836.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638011637437) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 22803932 + ... + 22831892.

It is an arithmetic number, because the mean of its divisors is an integer number (20277553065).

Almost surely, 2^638011637432 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 638011637432, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (648881698080).

638011637432 is an abundant number, since it is smaller than the sum of its proper divisors (659751758728).

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

638011637432 is a wasteful number, since it uses less digits than its factorization.

638011637432 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29584 (or 29580 counting only the distinct ones).

The product of its (nonzero) digits is 435456, while the sum is 44.

The spelling of 638011637432 in words is "six hundred thirty-eight billion, eleven million, six hundred thirty-seven thousand, four hundred thirty-two".