9999000720 has 80 divisors (see below), whose sum is σ = 34441009920. Its totient is φ = 2666399616.

The previous prime is 9999000709. The next prime is 9999000761. The reversal of 9999000720 is 270009999.

It is a tau number, because it is divible by the number of its divisors (80).

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2312424 + ... + 2316743.

It is an arithmetic number, because the mean of its divisors is an integer number (430512624).

Almost surely, 2^9999000720 is an apocalyptic number.

9999000720 is a gapful number since it is divisible by the number (90) formed by its first and last digit.

It is an amenable number.

9999000720 is an abundant number, since it is smaller than the sum of its proper divisors (24442009200).

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

9999000720 is a wasteful number, since it uses less digits than its factorization.

9999000720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4629189 (or 4629177 counting only the distinct ones).

The product of its (nonzero) digits is 91854, while the sum is 45.

The square root of 9999000720 is about 99995.0034751737. The cubic root of 9999000720 is about 2154.3629248581.

The spelling of 9999000720 in words is "nine billion, nine hundred ninety-nine million, seven hundred twenty", and thus it is an aban number.