19645596161 has 2 divisors, whose sum is σ = 19645596162. Its totient is φ = 19645596160.

The previous prime is 19645596149. The next prime is 19645596199. The reversal of 19645596161 is 16169554691.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18997384561 + 648211600 = 137831^2 + 25460^2 .

It is a cyclic number.

It is not a de Polignac number, because 19645596161 - 2⁶ = 19645596097 is a prime.

It is not a weakly prime, because it can be changed into another prime (19645590161) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9822798080 + 9822798081.

It is an arithmetic number, because the mean of its divisors is an integer number (9822798081).

Almost surely, 2^19645596161 is an apocalyptic number.

It is an amenable number.

19645596161 is a deficient number, since it is larger than the sum of its proper divisors (1).

19645596161 is an equidigital number, since it uses as much as digits as its factorization.

19645596161 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1749600, while the sum is 53.

The spelling of 19645596161 in words is "nineteen billion, six hundred forty-five million, five hundred ninety-six thousand, one hundred sixty-one".