638407365617 has 8 divisors (see below), whose sum is σ = 731003466816. Its totient is φ = 546160026672.

The previous prime is 638407365571. The next prime is 638407365619. The reversal of 638407365617 is 716563704836.

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 638407365617 - 2³⁰ = 637333623793 is a prime.

It is not an unprimeable number, because it can be changed into a prime (638407365619) 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, 87186638 + ... + 87193959.

It is an arithmetic number, because the mean of its divisors is an integer number (91375433352).

Almost surely, 2^638407365617 is an apocalyptic number.

It is an amenable number.

638407365617 is a deficient number, since it is larger than the sum of its proper divisors (92596101199).

638407365617 is a wasteful number, since it uses less digits than its factorization.

638407365617 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 174381127.

The product of its (nonzero) digits is 15240960, while the sum is 56.

The spelling of 638407365617 in words is "six hundred thirty-eight billion, four hundred seven million, three hundred sixty-five thousand, six hundred seventeen".