638440252 has 6 divisors (see below), whose sum is σ = 1117270448. Its totient is φ = 319220124.

The previous prime is 638440241. The next prime is 638440259. The reversal of 638440252 is 252044836.

638440252 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638440259) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 79805028 + ... + 79805035.

Almost surely, 2^638440252 is an apocalyptic number.

It is an amenable number.

638440252 is a deficient number, since it is larger than the sum of its proper divisors (478830196).

638440252 is a wasteful number, since it uses less digits than its factorization.

638440252 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 159610067 (or 159610065 counting only the distinct ones).

The product of its (nonzero) digits is 46080, while the sum is 34.

The square root of 638440252 is about 25267.3752495189. The cubic root of 638440252 is about 861.0732283534.

The spelling of 638440252 in words is "six hundred thirty-eight million, four hundred forty thousand, two hundred fifty-two".