19689489217 has 2 divisors, whose sum is σ = 19689489218. Its totient is φ = 19689489216.

The previous prime is 19689489161. The next prime is 19689489277. The reversal of 19689489217 is 71298498691.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14018796801 + 5670692416 = 118401^2 + 75304^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19689489217 is a prime.

It is not a weakly prime, because it can be changed into another prime (19689489277) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9844744608 + 9844744609.

It is an arithmetic number, because the mean of its divisors is an integer number (9844744609).

Almost surely, 2^19689489217 is an apocalyptic number.

It is an amenable number.

19689489217 is a deficient number, since it is larger than the sum of its proper divisors (1).

19689489217 is an equidigital number, since it uses as much as digits as its factorization.

19689489217 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 15676416, while the sum is 64.

The spelling of 19689489217 in words is "nineteen billion, six hundred eighty-nine million, four hundred eighty-nine thousand, two hundred seventeen".