636587068021 has 2 divisors, whose sum is σ = 636587068022. Its totient is φ = 636587068020.

The previous prime is 636587068001. The next prime is 636587068067. The reversal of 636587068021 is 120860785636.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 510994795921 + 125592272100 = 714839^2 + 354390^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-636587068021 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 636587068021.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (636587068001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 318293534010 + 318293534011.

It is an arithmetic number, because the mean of its divisors is an integer number (318293534011).

Almost surely, 2^636587068021 is an apocalyptic number.

It is an amenable number.

636587068021 is a deficient number, since it is larger than the sum of its proper divisors (1).

636587068021 is an equidigital number, since it uses as much as digits as its factorization.

636587068021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2903040, while the sum is 52.

The spelling of 636587068021 in words is "six hundred thirty-six billion, five hundred eighty-seven million, sixty-eight thousand, twenty-one".