9999900 has 108 divisors (see below), whose sum is σ = 32227104. Its totient is φ = 2592000.

The previous prime is 9999889. The next prime is 9999901. The reversal of 9999900 is 99999.

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

It is a nialpdrome in base 10.

It is a zygodrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9999901) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 36765 + ... + 37035.

Almost surely, 2^9999900 is an apocalyptic number.

9999900 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 9999900, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (16113552).

9999900 is an abundant number, since it is smaller than the sum of its proper divisors (22227204).

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

9999900 is a wasteful number, since it uses less digits than its factorization.

9999900 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 332 (or 322 counting only the distinct ones).

The product of its (nonzero) digits is 59049, while the sum is 45.

The square root of 9999900 is about 3162.2618487405. The cubic root of 9999900 is about 215.4427508559.

Multiplying 9999900 by its reverse (99999), we get a square (999980000100 = 999990²).

9999900 divided by its reverse (99999) gives a square (100 = 10²).

It can be divided in two parts, 99 and 99900, that added together give a palindrome (99999).

The spelling of 9999900 in words is "nine million, nine hundred ninety-nine thousand, nine hundred".