19646660797 has 2 divisors, whose sum is σ = 19646660798. Its totient is φ = 19646660796.

The previous prime is 19646660783. The next prime is 19646660833. The reversal of 19646660797 is 79706664691.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16237385476 + 3409275321 = 127426^2 + 58389^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19646660797 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19646660717) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9823330398 + 9823330399.

It is an arithmetic number, because the mean of its divisors is an integer number (9823330399).

Almost surely, 2^19646660797 is an apocalyptic number.

It is an amenable number.

19646660797 is a deficient number, since it is larger than the sum of its proper divisors (1).

19646660797 is an equidigital number, since it uses as much as digits as its factorization.

19646660797 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 20575296, while the sum is 61.

The spelling of 19646660797 in words is "nineteen billion, six hundred forty-six million, six hundred sixty thousand, seven hundred ninety-seven".