638318106865 has 8 divisors (see below), whose sum is σ = 806296556160. Its totient is φ = 483777933552.

The previous prime is 638318106859. The next prime is 638318106869. The reversal of 638318106865 is 568601813836.

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 638318106865 - 2²³ = 638309718257 is a prime.

It is not an unprimeable number, because it can be changed into a prime (638318106869) 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, 3359568889 + ... + 3359569078.

It is an arithmetic number, because the mean of its divisors is an integer number (100787069520).

Almost surely, 2^638318106865 is an apocalyptic number.

It is an amenable number.

638318106865 is a deficient number, since it is larger than the sum of its proper divisors (167978449295).

638318106865 is a wasteful number, since it uses less digits than its factorization.

638318106865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6719137991.

The product of its (nonzero) digits is 4976640, while the sum is 55.

The spelling of 638318106865 in words is "six hundred thirty-eight billion, three hundred eighteen million, one hundred six thousand, eight hundred sixty-five".