638613782647 has 2 divisors, whose sum is σ = 638613782648. Its totient is φ = 638613782646.

The previous prime is 638613782629. The next prime is 638613782669. The reversal of 638613782647 is 746287316836.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 638613782647 - 2⁷ = 638613782519 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (638613782347) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319306891323 + 319306891324.

It is an arithmetic number, because the mean of its divisors is an integer number (319306891324).

Almost surely, 2^638613782647 is an apocalyptic number.

638613782647 is a deficient number, since it is larger than the sum of its proper divisors (1).

638613782647 is an equidigital number, since it uses as much as digits as its factorization.

638613782647 is an evil number, because the sum of its binary digits is even.

The product of its digits is 48771072, while the sum is 61.

The spelling of 638613782647 in words is "six hundred thirty-eight billion, six hundred thirteen million, seven hundred eighty-two thousand, six hundred forty-seven".