19866596779 has 2 divisors, whose sum is σ = 19866596780. Its totient is φ = 19866596778.

The previous prime is 19866596777. The next prime is 19866596801. The reversal of 19866596779 is 97769566891.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 19866596779 - 2¹ = 19866596777 is a prime.

Together with 19866596777, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (19866596773) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9933298389 + 9933298390.

It is an arithmetic number, because the mean of its divisors is an integer number (9933298390).

Almost surely, 2^19866596779 is an apocalyptic number.

19866596779 is a deficient number, since it is larger than the sum of its proper divisors (1).

19866596779 is an equidigital number, since it uses as much as digits as its factorization.

19866596779 is an evil number, because the sum of its binary digits is even.

The product of its digits is 308629440, while the sum is 73.

The spelling of 19866596779 in words is "nineteen billion, eight hundred sixty-six million, five hundred ninety-six thousand, seven hundred seventy-nine".