209813345 has 12 divisors (see below), whose sum is σ = 292882644. Its totient is φ = 143871840.

The previous prime is 209813339. The next prime is 209813353. The reversal of 209813345 is 543318902.

209813345 is digitally balanced in base 2, 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 115004176 + 94809169 = 10724^2 + 9737^2 .

It is not a de Polignac number, because 209813345 - 2¹⁰ = 209812321 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (35).

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 427946 + ... + 428435.

It is an arithmetic number, because the mean of its divisors is an integer number (24406887).

Almost surely, 2^209813345 is an apocalyptic number.

It is an amenable number.

209813345 is a deficient number, since it is larger than the sum of its proper divisors (83069299).

209813345 is an equidigital number, since it uses as much as digits as its factorization.

209813345 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 856400 (or 856393 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 35.

The square root of 209813345 is about 14484.9351051360. The cubic root of 209813345 is about 594.2160378757.

The spelling of 209813345 in words is "two hundred nine million, eight hundred thirteen thousand, three hundred forty-five".