638271568 has 40 divisors (see below), whose sum is σ = 1357725600. Its totient is φ = 288263040.

The previous prime is 638271553. The next prime is 638271581. The reversal of 638271568 is 865172836.

It is a Smith number, since the sum of its digits (46) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16083 + ... + 39181.

It is an arithmetic number, because the mean of its divisors is an integer number (33943140).

Almost surely, 2^638271568 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 638271568, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (678862800).

638271568 is an abundant number, since it is smaller than the sum of its proper divisors (719454032).

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

638271568 is a wasteful number, since it uses less digits than its factorization.

638271568 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23275 (or 23269 counting only the distinct ones).

The product of its digits is 483840, while the sum is 46.

The square root of 638271568 is about 25264.0370487379. The cubic root of 638271568 is about 860.9973861896.

The spelling of 638271568 in words is "six hundred thirty-eight million, two hundred seventy-one thousand, five hundred sixty-eight".