638731082993 has 2 divisors, whose sum is σ = 638731082994. Its totient is φ = 638731082992.

The previous prime is 638731082947. The next prime is 638731083017. The reversal of 638731082993 is 399280137836.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 476573457649 + 162157625344 = 690343^2 + 402688^2 .

It is a cyclic number.

It is not a de Polignac number, because 638731082993 - 2⁶ = 638731082929 is a prime.

It is not a weakly prime, because it can be changed into another prime (638731082293) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319365541496 + 319365541497.

It is an arithmetic number, because the mean of its divisors is an integer number (319365541497).

Almost surely, 2^638731082993 is an apocalyptic number.

It is an amenable number.

638731082993 is a deficient number, since it is larger than the sum of its proper divisors (1).

638731082993 is an equidigital number, since it uses as much as digits as its factorization.

638731082993 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 11757312, while the sum is 59.

The spelling of 638731082993 in words is "six hundred thirty-eight billion, seven hundred thirty-one million, eighty-two thousand, nine hundred ninety-three".