19847370817 has 16 divisors (see below), whose sum is σ = 21140685072. Its totient is φ = 18568314880.

The previous prime is 19847370779. The next prime is 19847370847. The reversal of 19847370817 is 71807374891.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 419471361 + 19427899456 = 20481^2 + 139384^2 .

It is a cyclic number.

It is not a de Polignac number, because 19847370817 - 2¹¹ = 19847368769 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19847370847) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2535093 + ... + 2542909.

It is an arithmetic number, because the mean of its divisors is an integer number (1321292817).

Almost surely, 2^19847370817 is an apocalyptic number.

19847370817 is a gapful number since it is divisible by the number (17) formed by its first and last digit.

It is an amenable number.

19847370817 is a deficient number, since it is larger than the sum of its proper divisors (1293314255).

19847370817 is a wasteful number, since it uses less digits than its factorization.

19847370817 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8708.

The product of its (nonzero) digits is 2370816, while the sum is 55.

The spelling of 19847370817 in words is "nineteen billion, eight hundred forty-seven million, three hundred seventy thousand, eight hundred seventeen".