9999785539873 has 4 divisors (see below), whose sum is σ = 10017116191300. Its totient is φ = 9982454888448.

The previous prime is 9999785539859. The next prime is 9999785539879. The reversal of 9999785539873 is 3789355879999.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 9476004769344 + 523780770529 = 3078312^2 + 723727^2 .

It is a cyclic number.

It is not a de Polignac number, because 9999785539873 - 2⁹ = 9999785539361 is a prime.

It is a super-2 number, since 2×9999785539873² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (9999785539879) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8665324848 + ... + 8665326001.

It is an arithmetic number, because the mean of its divisors is an integer number (2504279047825).

Almost surely, 2^{9999785539873} is an apocalyptic number.

It is an amenable number.

9999785539873 is a deficient number, since it is larger than the sum of its proper divisors (17330651427).

9999785539873 is a wasteful number, since it uses less digits than its factorization.

9999785539873 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17330651426.

The product of its digits is 41664974400, while the sum is 91.

The spelling of 9999785539873 in words is "nine trillion, nine hundred ninety-nine billion, seven hundred eighty-five million, five hundred thirty-nine thousand, eight hundred seventy-three".