209628240 has 80 divisors (see below), whose sum is σ = 672278400. Its totient is φ = 53971456.

The previous prime is 209628217. The next prime is 209628247. The reversal of 209628240 is 42826902.

209628240 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (80).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (209628247) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8100 + ... + 22019.

It is an arithmetic number, because the mean of its divisors is an integer number (8403480).

Almost surely, 2^209628240 is an apocalyptic number.

209628240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

209628240 is an abundant number, since it is smaller than the sum of its proper divisors (462650160).

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

209628240 is a wasteful number, since it uses less digits than its factorization.

209628240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30164 (or 30158 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 33.

The square root of 209628240 is about 14478.5441257055. The cubic root of 209628240 is about 594.0412400938.

The spelling of 209628240 in words is "two hundred nine million, six hundred twenty-eight thousand, two hundred forty".