9999858816 has 192 divisors, whose sum is σ = 29374745400. Its totient is φ = 3264675840.

The previous prime is 9999858809. The next prime is 9999858863. The reversal of 9999858816 is 6188589999.

It can be written as a sum of positive squares in 4 ways, for example, as 8225764416 + 1774094400 = 90696^2 + 42120^2 .

It is a tau number, because it is divible by the number of its divisors (192).

It is a Harshad number since it is a multiple of its sum of digits (72).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 12179686 + ... + 12180506.

Almost surely, 2^9999858816 is an apocalyptic number.

9999858816 is a gapful number since it is divisible by the number (96) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 9999858816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (14687372700).

9999858816 is an abundant number, since it is smaller than the sum of its proper divisors (19374886584).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

9999858816 is a wasteful number, since it uses less digits than its factorization.

9999858816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1047 (or 1032 counting only the distinct ones).

The product of its digits is 100776960, while the sum is 72.

The square root of 9999858816 is about 99999.2940775084. The cubic root of 9999858816 is about 2154.4245509273.

The spelling of 9999858816 in words is "nine billion, nine hundred ninety-nine million, eight hundred fifty-eight thousand, eight hundred sixteen".