638844867005 has 16 divisors (see below), whose sum is σ = 804885361920. Its totient is φ = 486087615552.

The previous prime is 638844866999. The next prime is 638844867079. The reversal of 638844867005 is 500768448836.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 638844867005 - 2⁸ = 638844866749 is a prime.

It is a super-2 number, since 2×638844867005² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 32869589 + ... + 32889018.

It is an arithmetic number, because the mean of its divisors is an integer number (50305335120).

Almost surely, 2^638844867005 is an apocalyptic number.

It is an amenable number.

638844867005 is a deficient number, since it is larger than the sum of its proper divisors (166040494915).

638844867005 is a wasteful number, since it uses less digits than its factorization.

638844867005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65758708.

The product of its (nonzero) digits is 30965760, while the sum is 59.

The spelling of 638844867005 in words is "six hundred thirty-eight billion, eight hundred forty-four million, eight hundred sixty-seven thousand, five".