638834831 has 4 divisors (see below), whose sum is σ = 649662600. Its totient is φ = 628007064.

The previous prime is 638834813. The next prime is 638834849. The reversal of 638834831 is 138438836.

638834831 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (638834813) and next prime (638834849).

It is a cyclic number.

It is not a de Polignac number, because 638834831 - 2¹⁸ = 638572687 is a prime.

It is a super-2 number, since 2×638834831² = 816219882597597122, which contains 22 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 (638833831) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5413796 + ... + 5413913.

It is an arithmetic number, because the mean of its divisors is an integer number (162415650).

Almost surely, 2^638834831 is an apocalyptic number.

638834831 is a deficient number, since it is larger than the sum of its proper divisors (10827769).

638834831 is a wasteful number, since it uses less digits than its factorization.

638834831 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10827768.

The product of its digits is 331776, while the sum is 44.

The square root of 638834831 is about 25275.1821160600. The cubic root of 638834831 is about 861.2505832123.

The spelling of 638834831 in words is "six hundred thirty-eight million, eight hundred thirty-four thousand, eight hundred thirty-one".