638828634 has 32 divisors (see below), whose sum is σ = 1338591744. Its totient is φ = 202862000.

The previous prime is 638828633. The next prime is 638828639. The reversal of 638828634 is 436828836.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (638828633) 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, 25417 + ... + 43859.

It is an arithmetic number, because the mean of its divisors is an integer number (41830992).

Almost surely, 2^638828634 is an apocalyptic number.

638828634 is an abundant number, since it is smaller than the sum of its proper divisors (699763110).

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

638828634 is a wasteful number, since it uses less digits than its factorization.

638828634 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18722.

The product of its digits is 1327104, while the sum is 48.

The square root of 638828634 is about 25275.0595251525. The cubic root of 638828634 is about 861.2477983573.

The spelling of 638828634 in words is "six hundred thirty-eight million, eight hundred twenty-eight thousand, six hundred thirty-four".