638828635 has 16 divisors (see below), whose sum is σ = 814586976. Its totient is φ = 479282688.

The previous prime is 638828633. The next prime is 638828639. The reversal of 638828635 is 536828836.

It is a cyclic number.

It is not a de Polignac number, because 638828635 - 2¹ = 638828633 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (638828633) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10777 + ... + 37333.

It is an arithmetic number, because the mean of its divisors is an integer number (50911686).

Almost surely, 2^638828635 is an apocalyptic number.

638828635 is a deficient number, since it is larger than the sum of its proper divisors (175758341).

638828635 is a wasteful number, since it uses less digits than its factorization.

638828635 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26862.

The product of its digits is 1658880, while the sum is 49.

The square root of 638828635 is about 25275.0595449348. The cubic root of 638828635 is about 861.2477988067.

The spelling of 638828635 in words is "six hundred thirty-eight million, eight hundred twenty-eight thousand, six hundred thirty-five".