245509 has 6 divisors (see below), whose sum is σ = 269990. Its totient is φ = 223080.

The previous prime is 245501. The next prime is 245513. The reversal of 245509 is 905542.

It can be written as a sum of positive squares in only one way, i.e., 245025 + 484 = 495^2 + 22^2 .

It is not a de Polignac number, because 245509 - 2³ = 245501 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (245501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 894 + ... + 1135.

2²⁴⁵⁵⁰⁹ is an apocalyptic number.

It is an amenable number.

245509 is a deficient number, since it is larger than the sum of its proper divisors (24481).

245509 is a wasteful number, since it uses less digits than its factorization.

245509 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2051 (or 2040 counting only the distinct ones).

The product of its (nonzero) digits is 1800, while the sum is 25.

The square root of 245509 is about 495.4886477004. The cubic root of 245509 is about 62.6165505205.

The spelling of 245509 in words is "two hundred forty-five thousand, five hundred nine".