638934618535 has 4 divisors (see below), whose sum is σ = 766721542248. Its totient is φ = 511147694824.

The previous prime is 638934618527. The next prime is 638934618571. The reversal of 638934618535 is 535816439836.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 638934618535 - 2³ = 638934618527 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 63893461849 + ... + 63893461858.

It is an arithmetic number, because the mean of its divisors is an integer number (191680385562).

Almost surely, 2^638934618535 is an apocalyptic number.

638934618535 is a deficient number, since it is larger than the sum of its proper divisors (127786923713).

638934618535 is a wasteful number, since it uses less digits than its factorization.

638934618535 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 127786923712.

The product of its digits is 55987200, while the sum is 61.

The spelling of 638934618535 in words is "six hundred thirty-eight billion, nine hundred thirty-four million, six hundred eighteen thousand, five hundred thirty-five".