638818868711 has 8 divisors (see below), whose sum is σ = 668459163264. Its totient is φ = 609743151360.

The previous prime is 638818868671. The next prime is 638818868713. The reversal of 638818868711 is 117868818836.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 638818868711 - 2²⁶ = 638751759847 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638818868713) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 141141986 + ... + 141146511.

It is an arithmetic number, because the mean of its divisors is an integer number (83557395408).

Almost surely, 2^638818868711 is an apocalyptic number.

638818868711 is a deficient number, since it is larger than the sum of its proper divisors (29640294553).

638818868711 is a wasteful number, since it uses less digits than its factorization.

638818868711 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 282288601.

The product of its digits is 24772608, while the sum is 65.

The spelling of 638818868711 in words is "six hundred thirty-eight billion, eight hundred eighteen million, eight hundred sixty-eight thousand, seven hundred eleven".