638655661713 has 8 divisors (see below), whose sum is σ = 851711654368. Its totient is φ = 425685055104.

The previous prime is 638655661703. The next prime is 638655661727. The reversal of 638655661713 is 317166556836.

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

It is not a de Polignac number, because 638655661713 - 2³⁶ = 569936184977 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (638655661703) 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, 21329056 + ... + 21358977.

It is an arithmetic number, because the mean of its divisors is an integer number (106463956796).

Almost surely, 2^638655661713 is an apocalyptic number.

It is an amenable number.

638655661713 is a deficient number, since it is larger than the sum of its proper divisors (213055992655).

638655661713 is a wasteful number, since it uses less digits than its factorization.

638655661713 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42693023.

The product of its digits is 16329600, while the sum is 57.

The spelling of 638655661713 in words is "six hundred thirty-eight billion, six hundred fifty-five million, six hundred sixty-one thousand, seven hundred thirteen".