9859998817 has 2 divisors, whose sum is σ = 9859998818. Its totient is φ = 9859998816.

The previous prime is 9859998779. The next prime is 9859998829. The reversal of 9859998817 is 7188999589.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 9850364001 + 9634816 = 99249^2 + 3104^2 .

It is an emirp because it is prime and its reverse (7188999589) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 9859998817 - 2¹⁹ = 9859474529 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 9859998817.

It is not a weakly prime, because it can be changed into another prime (9859998847) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4929999408 + 4929999409.

It is an arithmetic number, because the mean of its divisors is an integer number (4929999409).

Almost surely, 2^9859998817 is an apocalyptic number.

It is an amenable number.

9859998817 is a deficient number, since it is larger than the sum of its proper divisors (1).

9859998817 is an equidigital number, since it uses as much as digits as its factorization.

9859998817 is an evil number, because the sum of its binary digits is even.

The product of its digits is 117573120, while the sum is 73.

The square root of 9859998817 is about 99297.5267416062. The cubic root of 9859998817 is about 2144.3332885543. Note that the first 3 decimals are identical.

The spelling of 9859998817 in words is "nine billion, eight hundred fifty-nine million, nine hundred ninety-eight thousand, eight hundred seventeen".