9090900 has 288 divisors, whose sum is σ = 36942080. Its totient is φ = 1866240.

The previous prime is 9090871. The next prime is 9090901. The reversal of 9090900 is 90909.

9090900 is nontrivially palindromic in base 8.

9090900 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a super Niven number, because it is divisible the sum of any subset of its (nonzero) digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9090901) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 245682 + ... + 245718.

Almost surely, 2^9090900 is an apocalyptic number.

9090900 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 9090900, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (18471040).

9090900 is an abundant number, since it is smaller than the sum of its proper divisors (27851180).

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

9090900 is a wasteful number, since it uses less digits than its factorization.

9090900 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80 (or 67 counting only the distinct ones).

The product of its (nonzero) digits is 729, while the sum is 27.

The square root of 9090900 is about 3015.1119382205. Note that the first 3 decimals coincide. The cubic root of 9090900 is about 208.7063326735.

Multiplying 9090900 by its reverse (90909), we get a square (826444628100 = 909090²).

9090900 divided by its reverse (90909) gives a square (100 = 10²).

The spelling of 9090900 in words is "nine million, ninety thousand, nine hundred".