225805 has 4 divisors (see below), whose sum is σ = 270972. Its totient is φ = 180640.

The previous prime is 225781. The next prime is 225809. The reversal of 225805 is 508522.

225805 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 125316 + 100489 = 354^2 + 317^2 .

It is not a de Polignac number, because 225805 - 2¹¹ = 223757 is a prime.

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an Ulam number.

It is a Duffinian number.

225805 is a lucky number.

It is a nialpdrome in base 12.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (225809) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22576 + ... + 22585.

It is an arithmetic number, because the mean of its divisors is an integer number (67743).

2²²⁵⁸⁰⁵ is an apocalyptic number.

It is an amenable number.

225805 is a deficient number, since it is larger than the sum of its proper divisors (45167).

225805 is an equidigital number, since it uses as much as digits as its factorization.

225805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45166.

The product of its (nonzero) digits is 800, while the sum is 22.

The square root of 225805 is about 475.1894359095. The cubic root of 225805 is about 60.8944695120.

The spelling of 225805 in words is "two hundred twenty-five thousand, eight hundred five".