638815374173 has 2 divisors, whose sum is σ = 638815374174. Its totient is φ = 638815374172.

The previous prime is 638815374089. The next prime is 638815374187. The reversal of 638815374173 is 371473518836.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 437445991609 + 201369382564 = 661397^2 + 448742^2 .

It is a cyclic number.

It is not a de Polignac number, because 638815374173 - 2¹⁰ = 638815373149 is a prime.

It is a Sophie Germain 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 (638815370173) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319407687086 + 319407687087.

It is an arithmetic number, because the mean of its divisors is an integer number (319407687087).

Almost surely, 2^638815374173 is an apocalyptic number.

It is an amenable number.

638815374173 is a deficient number, since it is larger than the sum of its proper divisors (1).

638815374173 is an equidigital number, since it uses as much as digits as its factorization.

638815374173 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10160640, while the sum is 56.

The spelling of 638815374173 in words is "six hundred thirty-eight billion, eight hundred fifteen million, three hundred seventy-four thousand, one hundred seventy-three".