638000495989 has 2 divisors, whose sum is σ = 638000495990. Its totient is φ = 638000495988.

The previous prime is 638000495983. The next prime is 638000496017. The reversal of 638000495989 is 989594000836.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 458893791889 + 179106704100 = 677417^2 + 423210^2 .

It is a cyclic number.

It is not a de Polignac number, because 638000495989 - 2³ = 638000495981 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (638000495981) 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, 319000247994 + 319000247995.

It is an arithmetic number, because the mean of its divisors is an integer number (319000247995).

Almost surely, 2^638000495989 is an apocalyptic number.

It is an amenable number.

638000495989 is a deficient number, since it is larger than the sum of its proper divisors (1).

638000495989 is an equidigital number, since it uses as much as digits as its factorization.

638000495989 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 16796160, while the sum is 61.

The spelling of 638000495989 in words is "six hundred thirty-eight billion, four hundred ninety-five thousand, nine hundred eighty-nine".