638671036 has 6 divisors (see below), whose sum is σ = 1117674320. Its totient is φ = 319335516.

The previous prime is 638671027. The next prime is 638671039. The reversal of 638671036 is 630176836.

It is a self number, because there is not a number n which added to its sum of digits gives 638671036.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638671039) 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 as a sum of consecutive naturals, namely, 79833876 + ... + 79833883.

Almost surely, 2^638671036 is an apocalyptic number.

It is an amenable number.

638671036 is a deficient number, since it is larger than the sum of its proper divisors (479003284).

638671036 is a wasteful number, since it uses less digits than its factorization.

638671036 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 159667763 (or 159667761 counting only the distinct ones).

The product of its (nonzero) digits is 108864, while the sum is 40.

The square root of 638671036 is about 25271.9416745133. The cubic root of 638671036 is about 861.1769697155.

The spelling of 638671036 in words is "six hundred thirty-eight million, six hundred seventy-one thousand, thirty-six".