638174238 has 64 divisors (see below), whose sum is σ = 1446100992. Its totient is φ = 186278400.

The previous prime is 638174213. The next prime is 638174239. The reversal of 638174238 is 832471836.

It is a self number, because there is not a number n which added to its sum of digits gives 638174238.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638174239) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 226438 + ... + 229238.

It is an arithmetic number, because the mean of its divisors is an integer number (22595328).

Almost surely, 2^638174238 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 638174238, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (723050496).

638174238 is an abundant number, since it is smaller than the sum of its proper divisors (807926754).

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

638174238 is a wasteful number, since it uses less digits than its factorization.

638174238 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2969.

The product of its digits is 193536, while the sum is 42.

The square root of 638174238 is about 25262.1107194154. The cubic root of 638174238 is about 860.9536194818.

The spelling of 638174238 in words is "six hundred thirty-eight million, one hundred seventy-four thousand, two hundred thirty-eight".