900900 has 216 divisors, whose sum is σ = 3791424. Its totient is φ = 172800.

The previous prime is 900869. The next prime is 900917. The reversal of 900900 is 9009.

900900 = T₁₅₅ + T₁₅₆ + ... + T₂₀₈.

It is a Harshad number since it is a multiple of its sum of digits (18).

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

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 69294 + ... + 69306.

2⁹⁰⁰⁹⁰⁰ is an apocalyptic number.

900900 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 900900, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1895712).

900900 is an abundant number, since it is smaller than the sum of its proper divisors (2890524).

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

900900 is a wasteful number, since it uses less digits than its factorization.

900900 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51 (or 41 counting only the distinct ones).

The product of its (nonzero) digits is 81, while the sum is 18.

The square root of 900900 is about 949.1575211734. The cubic root of 900900 is about 96.5811107183.

Adding to 900900 its reverse (9009), we get a palindrome (909909).

Multiplying 900900 by its reverse (9009), we get a square (8116208100 = 90090²).

900900 divided by its reverse (9009) gives a square (100 = 10²).

The spelling of 900900 in words is "nine hundred thousand, nine hundred".