209900808 has 80 divisors (see below), whose sum is σ = 633166380. Its totient is φ = 64582272.

The previous prime is 209900807. The next prime is 209900839. The reversal of 209900808 is 808009902.

209900808 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 207878724 + 2022084 = 14418^2 + 1422^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (209900807) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 4035 + ... + 20882.

Almost surely, 2^209900808 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 209900808, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (316583190).

209900808 is an abundant number, since it is smaller than the sum of its proper divisors (423265572).

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

209900808 is a wasteful number, since it uses less digits than its factorization.

209900808 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24948 (or 24935 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 36.

The square root of 209900808 is about 14487.9538928035. The cubic root of 209900808 is about 594.2985949017.

The spelling of 209900808 in words is "two hundred nine million, nine hundred thousand, eight hundred eight".