245905 has 16 divisors (see below), whose sum is σ = 342144. Its totient is φ = 167680.

The previous prime is 245899. The next prime is 245909. The reversal of 245905 is 509542.

It is not a de Polignac number, because 245905 - 2³ = 245897 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 245905.

It is not an unprimeable number, because it can be changed into a prime (245909) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 804 + ... + 1066.

It is an arithmetic number, because the mean of its divisors is an integer number (21384).

2²⁴⁵⁹⁰⁵ is an apocalyptic number.

It is an amenable number.

245905 is a deficient number, since it is larger than the sum of its proper divisors (96239).

245905 is a wasteful number, since it uses less digits than its factorization.

245905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 296.

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

The square root of 245905 is about 495.8880922144. Note that the first 3 decimals coincide. The cubic root of 245905 is about 62.6501987562.

It can be divided in two parts, 24 and 5905, that added together give a square (5929 = 77²).

The spelling of 245905 in words is "two hundred forty-five thousand, nine hundred five".