638587144 has 64 divisors (see below), whose sum is σ = 1331447040. Its totient is φ = 285223680.

The previous prime is 638587139. The next prime is 638587153. The reversal of 638587144 is 441785836.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 638587094 and 638587103.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1011709 + ... + 1012339.

It is an arithmetic number, because the mean of its divisors is an integer number (20803860).

Almost surely, 2^638587144 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 638587144, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (665723520).

638587144 is an abundant number, since it is smaller than the sum of its proper divisors (692859896).

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

638587144 is a wasteful number, since it uses less digits than its factorization.

638587144 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 950 (or 946 counting only the distinct ones).

The product of its digits is 645120, while the sum is 46.

The square root of 638587144 is about 25270.2818345977. The cubic root of 638587144 is about 861.1392617157.

The spelling of 638587144 in words is "six hundred thirty-eight million, five hundred eighty-seven thousand, one hundred forty-four".