209145 has 16 divisors (see below), whose sum is σ = 340992. Its totient is φ = 109440.

The previous prime is 209123. The next prime is 209147. The reversal of 209145 is 541902.

It is not a de Polignac number, because 209145 - 2⁸ = 208889 is a prime.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 209145.

It is not an unprimeable number, because it can be changed into a prime (209147) 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, 1000 + ... + 1190.

It is an arithmetic number, because the mean of its divisors is an integer number (21312).

2²⁰⁹¹⁴⁵ is an apocalyptic number.

It is an amenable number.

209145 is a deficient number, since it is larger than the sum of its proper divisors (131847).

209145 is a wasteful number, since it uses less digits than its factorization.

209145 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 272.

The product of its (nonzero) digits is 360, while the sum is 21.

The square root of 209145 is about 457.3237365368. The cubic root of 209145 is about 59.3584422898.

The spelling of 209145 in words is "two hundred nine thousand, one hundred forty-five".