638636201663 has 2 divisors, whose sum is σ = 638636201664. Its totient is φ = 638636201662.

The previous prime is 638636201657. The next prime is 638636201737. The reversal of 638636201663 is 366102636836.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 638636201663 - 2¹⁸ = 638635939519 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (638636201603) 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, 319318100831 + 319318100832.

It is an arithmetic number, because the mean of its divisors is an integer number (319318100832).

Almost surely, 2^638636201663 is an apocalyptic number.

638636201663 is a deficient number, since it is larger than the sum of its proper divisors (1).

638636201663 is an equidigital number, since it uses as much as digits as its factorization.

638636201663 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3359232, while the sum is 50.

The spelling of 638636201663 in words is "six hundred thirty-eight billion, six hundred thirty-six million, two hundred one thousand, six hundred sixty-three".