9865439999 has 12 divisors (see below), whose sum is σ = 9993302064. Its totient is φ = 9739160064.

The previous prime is 9865439993. The next prime is 9865440001. The reversal of 9865439999 is 9999345689.

It is not a de Polignac number, because 9865439999 - 2⁸ = 9865439743 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 (9865439993) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4581107 + ... + 4583259.

It is an arithmetic number, because the mean of its divisors is an integer number (832775172).

Almost surely, 2^9865439999 is an apocalyptic number.

9865439999 is a deficient number, since it is larger than the sum of its proper divisors (127862065).

9865439999 is an equidigital number, since it uses as much as digits as its factorization.

9865439999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2834 (or 2737 counting only the distinct ones).

The product of its digits is 170061120, while the sum is 71.

The square root of 9865439999 is about 99324.9213390074. The cubic root of 9865439999 is about 2144.7276618977.

The spelling of 9865439999 in words is "nine billion, eight hundred sixty-five million, four hundred thirty-nine thousand, nine hundred ninety-nine".