638011636849 has 2 divisors, whose sum is σ = 638011636850. Its totient is φ = 638011636848.

The previous prime is 638011636841. The next prime is 638011636931. The reversal of 638011636849 is 948636110836.

638011636849 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 522971956224 + 115039680625 = 723168^2 + 339175^2 .

It is a cyclic number.

It is not a de Polignac number, because 638011636849 - 2³ = 638011636841 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 638011636849.

It is not a weakly prime, because it can be changed into another prime (638011636841) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319005818424 + 319005818425.

It is an arithmetic number, because the mean of its divisors is an integer number (319005818425).

Almost surely, 2^638011636849 is an apocalyptic number.

It is an amenable number.

638011636849 is a deficient number, since it is larger than the sum of its proper divisors (1).

638011636849 is an equidigital number, since it uses as much as digits as its factorization.

638011636849 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4478976, while the sum is 55.

The spelling of 638011636849 in words is "six hundred thirty-eight billion, eleven million, six hundred thirty-six thousand, eight hundred forty-nine".