Adding to 9999900000 its reverse (99999), we get a palindrome (9999999999).
Subtracting from 9999900000 its reverse (99999), we obtain a square (9999800001 = 999992).
9999900000 divided by its reverse (99999) gives a 5-th power (100000 = 105).
It is a nialpdrome in base 10.
It is a zygodrome in base 10.
It is a congruent number.
It is an unprimeable number.
Almost surely, 29999900000 is an apocalyptic number.
9999900000 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 9999900000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (18272767968).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
9999900000 is a wasteful number, since it uses less digits than its factorization.
9999900000 is an odious number, because the sum of its binary digits is odd.
The square root of 9999900000 is about 99999.4999987500. The cubic root of 9999900000 is about 2154.4275085590.
The spelling of 9999900000 in words is "nine billion, nine hundred ninety-nine million, nine hundred thousand".