638613621682 has 16 divisors (see below), whose sum is σ = 982594277280. Its totient is φ = 311118508512.

The previous prime is 638613621673. The next prime is 638613621691. The reversal of 638613621682 is 286126316836.

It is an interprime number because it is at equal distance from previous prime (638613621673) and next prime (638613621691).

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, 9042748 + ... + 9113095.

It is an arithmetic number, because the mean of its divisors is an integer number (61412142330).

Almost surely, 2^638613621682 is an apocalyptic number.

638613621682 is a deficient number, since it is larger than the sum of its proper divisors (343980655598).

638613621682 is a wasteful number, since it uses less digits than its factorization.

638613621682 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18156297.

The product of its digits is 2985984, while the sum is 52.

The spelling of 638613621682 in words is "six hundred thirty-eight billion, six hundred thirteen million, six hundred twenty-one thousand, six hundred eighty-two".