638876388 has 24 divisors (see below), whose sum is σ = 1578400992. Its totient is φ = 200431744.

The previous prime is 638876383. The next prime is 638876393. The reversal of 638876388 is 883678836.

It is an interprime number because it is at equal distance from previous prime (638876383) and next prime (638876393).

It is not an unprimeable number, because it can be changed into a prime (638876383) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1565670 + ... + 1566077.

It is an arithmetic number, because the mean of its divisors is an integer number (65766708).

Almost surely, 2^638876388 is an apocalyptic number.

638876388 is a gapful number since it is divisible by the number (68) formed by its first and last digit.

It is an amenable number.

638876388 is an abundant number, since it is smaller than the sum of its proper divisors (939524604).

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

638876388 is a wasteful number, since it uses less digits than its factorization.

638876388 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3131771 (or 3131769 counting only the distinct ones).

The product of its digits is 9289728, while the sum is 57.

The square root of 638876388 is about 25276.0041937012. The cubic root of 638876388 is about 861.2692579478.

The spelling of 638876388 in words is "six hundred thirty-eight million, eight hundred seventy-six thousand, three hundred eighty-eight".