638942382829 has 8 divisors (see below), whose sum is σ = 642831465528. Its totient is φ = 635064756480.

The previous prime is 638942382803. The next prime is 638942382847. The reversal of 638942382829 is 928283249836.

It can be written as a sum of positive squares in 4 ways, for example, as 50196162025 + 588746220804 = 224045^2 + 767298^2 .

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 638942382829 - 2¹⁷ = 638942251757 is a prime.

It is a super-3 number, since 3×638942382829³ (a number of 36 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638942382899) 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, 2752192 + ... + 2975305.

It is an arithmetic number, because the mean of its divisors is an integer number (80353933191).

Almost surely, 2^638942382829 is an apocalyptic number.

It is an amenable number.

638942382829 is a deficient number, since it is larger than the sum of its proper divisors (3889082699).

638942382829 is a wasteful number, since it uses less digits than its factorization.

638942382829 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5728175.

The product of its digits is 71663616, while the sum is 64.

The spelling of 638942382829 in words is "six hundred thirty-eight billion, nine hundred forty-two million, three hundred eighty-two thousand, eight hundred twenty-nine".