638893873 has 2 divisors, whose sum is σ = 638893874. Its totient is φ = 638893872.

The previous prime is 638893823. The next prime is 638893903. The reversal of 638893873 is 378398836.

638893873 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 347747904 + 291145969 = 18648^2 + 17063^2 .

It is a cyclic number.

It is not a de Polignac number, because 638893873 - 2⁹ = 638893361 is a prime.

It is not a weakly prime, because it can be changed into another prime (638893823) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319446936 + 319446937.

It is an arithmetic number, because the mean of its divisors is an integer number (319446937).

Almost surely, 2^638893873 is an apocalyptic number.

It is an amenable number.

638893873 is a deficient number, since it is larger than the sum of its proper divisors (1).

638893873 is an equidigital number, since it uses as much as digits as its factorization.

638893873 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5225472, while the sum is 55.

The square root of 638893873 is about 25276.3500727459. The cubic root of 638893873 is about 861.2771150523.

The spelling of 638893873 in words is "six hundred thirty-eight million, eight hundred ninety-three thousand, eight hundred seventy-three".