245309 has 4 divisors (see below), whose sum is σ = 258240. Its totient is φ = 232380.

The previous prime is 245299. The next prime is 245317. The reversal of 245309 is 903542.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 903542 = 2 ⋅451771.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-245309 is a prime.

It is a house number.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (245339) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6437 + ... + 6474.

It is an arithmetic number, because the mean of its divisors is an integer number (64560).

2²⁴⁵³⁰⁹ is an apocalyptic number.

It is an amenable number.

245309 is a deficient number, since it is larger than the sum of its proper divisors (12931).

245309 is a wasteful number, since it uses less digits than its factorization.

245309 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12930.

The product of its (nonzero) digits is 1080, while the sum is 23.

The square root of 245309 is about 495.2867856101. The cubic root of 245309 is about 62.5995427092.

The spelling of 245309 in words is "two hundred forty-five thousand, three hundred nine".