638776538 has 8 divisors (see below), whose sum is σ = 958813632. Its totient is φ = 319171996.

The previous prime is 638776529. The next prime is 638776571. The reversal of 638776538 is 835677836.

638776538 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a self number, because there is not a number n which added to its sum of digits gives 638776538.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 104420 + ... + 110367.

It is an arithmetic number, because the mean of its divisors is an integer number (119851704).

Almost surely, 2^638776538 is an apocalyptic number.

638776538 is a deficient number, since it is larger than the sum of its proper divisors (320037094).

638776538 is a wasteful number, since it uses less digits than its factorization.

638776538 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 216276.

The product of its digits is 5080320, while the sum is 53.

The square root of 638776538 is about 25274.0289229873. The cubic root of 638776538 is about 861.2243863484.

The spelling of 638776538 in words is "six hundred thirty-eight million, seven hundred seventy-six thousand, five hundred thirty-eight".