209735145 has 12 divisors (see below), whose sum is σ = 363540996. Its totient is φ = 111858720.

The previous prime is 209735117. The next prime is 209735153. The reversal of 209735145 is 541537902.

It can be written as a sum of positive squares in 2 ways, for example, as 119180889 + 90554256 = 10917^2 + 9516^2 .

It is not a de Polignac number, because 209735145 - 2¹⁶ = 209669609 is a prime.

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, 2330346 + ... + 2330435.

It is an arithmetic number, because the mean of its divisors is an integer number (30295083).

Almost surely, 2^209735145 is an apocalyptic number.

It is an amenable number.

209735145 is a deficient number, since it is larger than the sum of its proper divisors (153805851).

209735145 is a wasteful number, since it uses less digits than its factorization.

209735145 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4660792 (or 4660789 counting only the distinct ones).

The product of its (nonzero) digits is 37800, while the sum is 36.

The square root of 209735145 is about 14482.2354973257. The cubic root of 209735145 is about 594.1422048403.

The spelling of 209735145 in words is "two hundred nine million, seven hundred thirty-five thousand, one hundred forty-five".