1638876664 has 16 divisors (see below), whose sum is σ = 3084854400. Its totient is φ = 816248832.

The previous prime is 1638876649. The next prime is 1638876671. The reversal of 1638876664 is 4666788361.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 396504 + ... + 400615.

It is an arithmetic number, because the mean of its divisors is an integer number (192803400).

Almost surely, 2^1638876664 is an apocalyptic number.

It is an amenable number.

1638876664 is a deficient number, since it is larger than the sum of its proper divisors (1445977736).

1638876664 is a wasteful number, since it uses less digits than its factorization.

1638876664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 797382 (or 797378 counting only the distinct ones).

The product of its digits is 6967296, while the sum is 55.

The square root of 1638876664 is about 40483.0416841423. The cubic root of 1638876664 is about 1179.0043943384.

The spelling of 1638876664 in words is "one billion, six hundred thirty-eight million, eight hundred seventy-six thousand, six hundred sixty-four".