638000813 has 2 divisors, whose sum is σ = 638000814. Its totient is φ = 638000812.

The previous prime is 638000809. The next prime is 638000827. The reversal of 638000813 is 318000836.

638000813 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 396726724 + 241274089 = 19918^2 + 15533^2 .

It is a cyclic number.

It is not a de Polignac number, because 638000813 - 2² = 638000809 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (638000843) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319000406 + 319000407.

It is an arithmetic number, because the mean of its divisors is an integer number (319000407).

Almost surely, 2^638000813 is an apocalyptic number.

It is an amenable number.

638000813 is a deficient number, since it is larger than the sum of its proper divisors (1).

638000813 is an equidigital number, since it uses as much as digits as its factorization.

638000813 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3456, while the sum is 29.

The square root of 638000813 is about 25258.6779741142. The cubic root of 638000813 is about 860.8756238500.

The spelling of 638000813 in words is "six hundred thirty-eight million, eight hundred thirteen", and thus it is an aban number.