19947643896609 has 144 divisors (see below), whose sum is σ = 34867096992000. Its totient is φ = 10911290734080.

The previous prime is 19947643896581. The next prime is 19947643896617. The reversal of 19947643896609 is 90669834674991.

19947643896609 is a `hidden beast` number, since 1 + 9 + 9 + 476 + 4 + 3 + 89 + 6 + 60 + 9 = 666.

It is not a de Polignac number, because 19947643896609 - 2¹⁵ = 19947643863841 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (19947643896629) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 697968282 + ... + 697996860.

It is an arithmetic number, because the mean of its divisors is an integer number (242132618000).

Almost surely, 2^{19947643896609} is an apocalyptic number.

It is an amenable number.

19947643896609 is a deficient number, since it is larger than the sum of its proper divisors (14919453095391).

19947643896609 is a wasteful number, since it uses less digits than its factorization.

19947643896609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29716 (or 29702 counting only the distinct ones).

The product of its (nonzero) digits is 3809369088, while the sum is 81.

The spelling of 19947643896609 in words is "nineteen trillion, nine hundred forty-seven billion, six hundred forty-three million, eight hundred ninety-six thousand, six hundred nine".