209812304 has 40 divisors (see below), whose sum is σ = 440279112. Its totient is φ = 96284160.

The previous prime is 209812301. The next prime is 209812321. The reversal of 209812304 is 403218902.

It can be written as a sum of positive squares in 4 ways, for example, as 36626704 + 173185600 = 6052^2 + 13160^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (209812301) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 34862 + ... + 40434.

Almost surely, 2^209812304 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 209812304, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (220139556).

209812304 is an abundant number, since it is smaller than the sum of its proper divisors (230466808).

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

209812304 is a wasteful number, since it uses less digits than its factorization.

209812304 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5775 (or 5769 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 29.

The square root of 209812304 is about 14484.8991712059. The cubic root of 209812304 is about 594.2150551293.

The spelling of 209812304 in words is "two hundred nine million, eight hundred twelve thousand, three hundred four".