638055688 has 8 divisors (see below), whose sum is σ = 1196354430. Its totient is φ = 319027840.

The previous prime is 638055667. The next prime is 638055721. The reversal of 638055688 is 886550836.

It can be written as a sum of positive squares in only one way, i.e., 557809924 + 80245764 = 23618^2 + 8958^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 39878473 + ... + 39878488.

Almost surely, 2^638055688 is an apocalyptic number.

It is an amenable number.

638055688 is a deficient number, since it is larger than the sum of its proper divisors (558298742).

638055688 is a wasteful number, since it uses less digits than its factorization.

638055688 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 79756967 (or 79756963 counting only the distinct ones).

The product of its (nonzero) digits is 1382400, while the sum is 49.

The square root of 638055688 is about 25259.7642110927. The cubic root of 638055688 is about 860.9003046940.

The spelling of 638055688 in words is "six hundred thirty-eight million, fifty-five thousand, six hundred eighty-eight".