638865364258 has 16 divisors (see below), whose sum is σ = 1053046829664. Its totient is φ = 288273686560.

The previous prime is 638865364243. The next prime is 638865364297. The reversal of 638865364258 is 852463568836.

It is a self number, because there is not a number n which added to its sum of digits gives 638865364258.

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, 105979960 + ... + 105985987.

It is an arithmetic number, because the mean of its divisors is an integer number (65815426854).

Almost surely, 2^638865364258 is an apocalyptic number.

638865364258 is a deficient number, since it is larger than the sum of its proper divisors (414181465406).

638865364258 is a wasteful number, since it uses less digits than its factorization.

638865364258 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 211966097.

The product of its digits is 199065600, while the sum is 64.

The spelling of 638865364258 in words is "six hundred thirty-eight billion, eight hundred sixty-five million, three hundred sixty-four thousand, two hundred fifty-eight".