638869308 has 144 divisors (see below), whose sum is σ = 1904980224. Its totient is φ = 161890560.

The previous prime is 638869307. The next prime is 638869331. The reversal of 638869308 is 803968836.

638869308 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 (638869307) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2040960 + ... + 2041272.

Almost surely, 2^638869308 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 638869308, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (952490112).

638869308 is an abundant number, since it is smaller than the sum of its proper divisors (1266110916).

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

638869308 is a wasteful number, since it uses less digits than its factorization.

638869308 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 432 (or 383 counting only the distinct ones).

The product of its (nonzero) digits is 1492992, while the sum is 51.

The square root of 638869308 is about 25275.8641395304. The cubic root of 638869308 is about 861.2660764201.

The spelling of 638869308 in words is "six hundred thirty-eight million, eight hundred sixty-nine thousand, three hundred eight".