9999800000 has 84 divisors (see below), whose sum is σ = 24803100000. Its totient is φ = 3999840000.

The previous prime is 9999799951. The next prime is 9999800003. The reversal of 9999800000 is 89999.

It is a Cunningham number, because it is equal to 99999²-1.

It is a nialpdrome in base 10.

It is not an unprimeable number, because it can be changed into a prime (9999800003) 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, 175001 + ... + 224999.

It is an arithmetic number, because the mean of its divisors is an integer number (295275000).

Almost surely, 2^9999800000 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 9999800000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (12401550000).

9999800000 is an abundant number, since it is smaller than the sum of its proper divisors (14803300000).

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

9999800000 is an frugal number, since it uses more digits than its factorization.

9999800000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50036 (or 50006 counting only the distinct ones).

The product of its (nonzero) digits is 52488, while the sum is 44.

The square root of 9999800000 is about 99998.9999949999. Note that the first 5 decimals coincide. The cubic root of 9999800000 is about 2154.4203270382.

Adding to 9999800000 its reverse (89999), we get a palindrome (9999889999).

The spelling of 9999800000 in words is "nine billion, nine hundred ninety-nine million, eight hundred thousand".