638674788049 has 4 divisors (see below), whose sum is σ = 641983984036. Its totient is φ = 635365592064.

The previous prime is 638674788029. The next prime is 638674788119. The reversal of 638674788049 is 940887476836.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 234636578449 + 404038209600 = 484393^2 + 635640^2 .

It is a cyclic number.

It is not a de Polignac number, because 638674788049 - 2⁹ = 638674787537 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (638674788029) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1654597704 + ... + 1654598089.

It is an arithmetic number, because the mean of its divisors is an integer number (160495996009).

Almost surely, 2^638674788049 is an apocalyptic number.

It is an amenable number.

638674788049 is a deficient number, since it is larger than the sum of its proper divisors (3309195987).

638674788049 is a wasteful number, since it uses less digits than its factorization.

638674788049 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3309195986.

The product of its (nonzero) digits is 390168576, while the sum is 70.

The spelling of 638674788049 in words is "six hundred thirty-eight billion, six hundred seventy-four million, seven hundred eighty-eight thousand, forty-nine".