19543641709 has 12 divisors (see below), whose sum is σ = 19963767252. Its totient is φ = 19126886400.

The previous prime is 19543641707. The next prime is 19543641713. The reversal of 19543641709 is 90714634591.

It can be written as a sum of positive squares in 6 ways, for example, as 379392484 + 19164249225 = 19478^2 + 138435^2 .

It is not a de Polignac number, because 19543641709 - 2¹ = 19543641707 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19543641707) 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 11 ways as a sum of consecutive naturals, for example, 16949677 + ... + 16950829.

It is an arithmetic number, because the mean of its divisors is an integer number (1663647271).

Almost surely, 2^19543641709 is an apocalyptic number.

It is an amenable number.

19543641709 is a deficient number, since it is larger than the sum of its proper divisors (420125543).

19543641709 is an frugal number, since it uses more digits than its factorization.

19543641709 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2608 (or 1455 counting only the distinct ones).

The product of its (nonzero) digits is 816480, while the sum is 49.

The spelling of 19543641709 in words is "nineteen billion, five hundred forty-three million, six hundred forty-one thousand, seven hundred nine".