638636188139 has 2 divisors, whose sum is σ = 638636188140. Its totient is φ = 638636188138.

The previous prime is 638636188093. The next prime is 638636188159. The reversal of 638636188139 is 931881636836.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 638636188139 - 2¹⁶ = 638636122603 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (638636188159) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319318094069 + 319318094070.

It is an arithmetic number, because the mean of its divisors is an integer number (319318094070).

Almost surely, 2^638636188139 is an apocalyptic number.

638636188139 is a deficient number, since it is larger than the sum of its proper divisors (1).

638636188139 is an equidigital number, since it uses as much as digits as its factorization.

638636188139 is an evil number, because the sum of its binary digits is even.

The product of its digits is 26873856, while the sum is 62.

The spelling of 638636188139 in words is "six hundred thirty-eight billion, six hundred thirty-six million, one hundred eighty-eight thousand, one hundred thirty-nine".