639979642163 has 2 divisors, whose sum is σ = 639979642164. Its totient is φ = 639979642162.

The previous prime is 639979642103. The next prime is 639979642171. The reversal of 639979642163 is 361246979936.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 639979642163 - 2²⁸ = 639711206707 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 639979642163.

It is not a weakly prime, because it can be changed into another prime (639979642103) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319989821081 + 319989821082.

It is an arithmetic number, because the mean of its divisors is an integer number (319989821082).

Almost surely, 2^639979642163 is an apocalyptic number.

639979642163 is a deficient number, since it is larger than the sum of its proper divisors (1).

639979642163 is an equidigital number, since it uses as much as digits as its factorization.

639979642163 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 79361856, while the sum is 65.

The spelling of 639979642163 in words is "six hundred thirty-nine billion, nine hundred seventy-nine million, six hundred forty-two thousand, one hundred sixty-three".