638466686 has 16 divisors (see below), whose sum is σ = 1125130608. Its totient is φ = 267888000.

The previous prime is 638466679. The next prime is 638466721. The reversal of 638466686 is 686664836.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1115915 + ... + 1116486.

It is an arithmetic number, because the mean of its divisors is an integer number (70320663).

Almost surely, 2^638466686 is an apocalyptic number.

638466686 is a deficient number, since it is larger than the sum of its proper divisors (486663922).

638466686 is a wasteful number, since it uses less digits than its factorization.

638466686 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2232427.

The product of its digits is 5971968, while the sum is 53.

The square root of 638466686 is about 25267.8983296989. The cubic root of 638466686 is about 861.0851121570.

The spelling of 638466686 in words is "six hundred thirty-eight million, four hundred sixty-six thousand, six hundred eighty-six".