9999198720 has 720 divisors, whose sum is σ = 42735432168. Its totient is φ = 2146959360.

The previous prime is 9999198701. The next prime is 9999198743. The reversal of 9999198720 is 278919999.

9999198720 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 8291195136 + 1708003584 = 91056^2 + 41328^2 .

It is a tau number, because it is divible by the number of its divisors (720).

It is a Harshad number since it is a multiple of its sum of digits (63).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 19192060 + ... + 19192580.

Almost surely, 2^9999198720 is an apocalyptic number.

9999198720 is a gapful number since it is divisible by the number (90) 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 9999198720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21367716084).

9999198720 is an abundant number, since it is smaller than the sum of its proper divisors (32736233448).

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

9999198720 is a wasteful number, since it uses less digits than its factorization.

9999198720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 581 (or 555 counting only the distinct ones).

The product of its (nonzero) digits is 6613488, while the sum is 63.

The square root of 9999198720 is about 99995.9935197406. The cubic root of 9999198720 is about 2154.3771449806.

The spelling of 9999198720 in words is "nine billion, nine hundred ninety-nine million, one hundred ninety-eight thousand, seven hundred twenty".