636442062459989 has 2 divisors, whose sum is σ = 636442062459990. Its totient is φ = 636442062459988.

The previous prime is 636442062459851. The next prime is 636442062460079. The reversal of 636442062459989 is 989954260244636.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 631966404879364 + 4475657580625 = 25138942^2 + 2115575^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-636442062459989 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (636442062450989) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 318221031229994 + 318221031229995.

It is an arithmetic number, because the mean of its divisors is an integer number (318221031229995).

Almost surely, 2^{636442062459989} is an apocalyptic number.

It is an amenable number.

636442062459989 is a deficient number, since it is larger than the sum of its proper divisors (1).

636442062459989 is an equidigital number, since it uses as much as digits as its factorization.

636442062459989 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4837294080, while the sum is 77.

The spelling of 636442062459989 in words is "six hundred thirty-six trillion, four hundred forty-two billion, sixty-two million, four hundred fifty-nine thousand, nine hundred eighty-nine".