638555104 has 48 divisors (see below), whose sum is σ = 1388862720. Its totient is φ = 286565760.

The previous prime is 638555087. The next prime is 638555107. The reversal of 638555104 is 401555836.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638555107) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16327 + ... + 39289.

It is an arithmetic number, because the mean of its divisors is an integer number (28934640).

Almost surely, 2^638555104 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 638555104, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (694431360).

638555104 is an abundant number, since it is smaller than the sum of its proper divisors (750307616).

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

638555104 is a wasteful number, since it uses less digits than its factorization.

638555104 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23063 (or 23055 counting only the distinct ones).

The product of its (nonzero) digits is 72000, while the sum is 37.

The square root of 638555104 is about 25269.6478804118. The cubic root of 638555104 is about 861.1248594196.

The spelling of 638555104 in words is "six hundred thirty-eight million, five hundred fifty-five thousand, one hundred four".