638819377 has 16 divisors (see below), whose sum is σ = 740315520. Its totient is φ = 539908992.

The previous prime is 638819371. The next prime is 638819381. The reversal of 638819377 is 773918836.

It is a happy number.

It is not a de Polignac number, because 638819377 - 2³ = 638819369 is a prime.

It is not an unprimeable number, because it can be changed into a prime (638819371) 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, 494949 + ... + 496237.

It is an arithmetic number, because the mean of its divisors is an integer number (46269720).

Almost surely, 2^638819377 is an apocalyptic number.

It is an amenable number.

638819377 is a deficient number, since it is larger than the sum of its proper divisors (101496143).

638819377 is a wasteful number, since it uses less digits than its factorization.

638819377 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2232.

The product of its digits is 1524096, while the sum is 52.

The square root of 638819377 is about 25274.8763993021. The cubic root of 638819377 is about 861.2436383427.

The spelling of 638819377 in words is "six hundred thirty-eight million, eight hundred nineteen thousand, three hundred seventy-seven".