638929834 has 16 divisors (see below), whose sum is σ = 1052700480. Its totient is φ = 289491840.

The previous prime is 638929831. The next prime is 638929847. The reversal of 638929834 is 438929836.

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 7 ways as a sum of consecutive naturals, for example, 364647 + ... + 366394.

It is an arithmetic number, because the mean of its divisors is an integer number (65793780).

Almost surely, 2^638929834 is an apocalyptic number.

638929834 is a deficient number, since it is larger than the sum of its proper divisors (413770646).

638929834 is a wasteful number, since it uses less digits than its factorization.

638929834 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 731085.

The product of its digits is 2239488, while the sum is 52.

The square root of 638929834 is about 25277.0614193976. The cubic root of 638929834 is about 861.2932741290.

The spelling of 638929834 in words is "six hundred thirty-eight million, nine hundred twenty-nine thousand, eight hundred thirty-four".