638268288 has 128 divisors (see below), whose sum is σ = 1957616640. Its totient is φ = 180480000.

The previous prime is 638268263. The next prime is 638268289. The reversal of 638268288 is 882862836.

It is a tau number, because it is divible by the number of its divisors (128).

It is a nude number because it is divisible by every one of its digits.

It is a self number, because there is not a number n which added to its sum of digits gives 638268288.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638268289) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 270313 + ... + 272663.

It is an arithmetic number, because the mean of its divisors is an integer number (15293880).

Almost surely, 2^638268288 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 638268288, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (978808320).

638268288 is an abundant number, since it is smaller than the sum of its proper divisors (1319348352).

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

638268288 is a wasteful number, since it uses less digits than its factorization.

638268288 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2476 (or 2464 counting only the distinct ones).

The product of its digits is 1769472, while the sum is 51.

The square root of 638268288 is about 25263.9721342468. The cubic root of 638268288 is about 860.9959113334.

The spelling of 638268288 in words is "six hundred thirty-eight million, two hundred sixty-eight thousand, two hundred eighty-eight".