19973569872409 has 2 divisors, whose sum is σ = 19973569872410. Its totient is φ = 19973569872408.

The previous prime is 19973569872383. The next prime is 19973569872413. The reversal of 19973569872409 is 90427896537991.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19973569872400 + 9 = 4469180^2 + 3^2 .

It is a cyclic number.

It is not a de Polignac number, because 19973569872409 - 2⁷ = 19973569872281 is a prime.

It is not a weakly prime, because it can be changed into another prime (19973569872469) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9986784936204 + 9986784936205.

It is an arithmetic number, because the mean of its divisors is an integer number (9986784936205).

It is a 1-persistent number, because it is pandigital, but 2⋅19973569872409 = 39947139744818 is not.

Almost surely, 2^{19973569872409} is an apocalyptic number.

It is an amenable number.

19973569872409 is a deficient number, since it is larger than the sum of its proper divisors (1).

19973569872409 is an equidigital number, since it uses as much as digits as its factorization.

19973569872409 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1851776640, while the sum is 79.

The spelling of 19973569872409 in words is "nineteen trillion, nine hundred seventy-three billion, five hundred sixty-nine million, eight hundred seventy-two thousand, four hundred nine".