638929836 has 48 divisors (see below), whose sum is σ = 1753930080. Its totient is φ = 200448000.

The previous prime is 638929831. The next prime is 638929847.

638929836 is nontrivially palindromic in base 10.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an alternating number because its digits alternate between even and odd.

It is not an unprimeable number, because it can be changed into a prime (638929831) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 172165 + ... + 175836.

It is an arithmetic number, because the mean of its divisors is an integer number (36540210).

Almost surely, 2^638929836 is an apocalyptic number.

It is an amenable number.

638929836 is an abundant number, since it is smaller than the sum of its proper divisors (1115000244).

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

638929836 is a wasteful number, since it uses less digits than its factorization.

638929836 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 348031 (or 348023 counting only the distinct ones).

The product of its digits is 3359232, while the sum is 54.

The square root of 638929836 is about 25277.0614589592. The cubic root of 638929836 is about 861.2932750277.

The spelling of 638929836 in words is "six hundred thirty-eight million, nine hundred twenty-nine thousand, eight hundred thirty-six".