225909 has 10 divisors (see below), whose sum is σ = 337590. Its totient is φ = 150552.

The previous prime is 225889. The next prime is 225919. The reversal of 225909 is 909522.

225909 is digitally balanced in base 7, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 202500 + 23409 = 450^2 + 153^2 .

It is not a de Polignac number, because 225909 - 2⁷ = 225781 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

225909 is strictly pandigital in base 7.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 225909.

It is not an unprimeable number, because it can be changed into a prime (225919) 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 9 ways as a sum of consecutive naturals, for example, 1314 + ... + 1475.

It is an arithmetic number, because the mean of its divisors is an integer number (33759).

2²²⁵⁹⁰⁹ is an apocalyptic number.

It is an amenable number.

225909 is a deficient number, since it is larger than the sum of its proper divisors (111681).

225909 is an equidigital number, since it uses as much as digits as its factorization.

225909 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2801 (or 2792 counting only the distinct ones).

The product of its (nonzero) digits is 1620, while the sum is 27.

The square root of 225909 is about 475.2988533544. The cubic root of 225909 is about 60.9038168881.

Adding to 225909 its product of nonzero digits (1620), we get a square (227529 = 477²).

The spelling of 225909 in words is "two hundred twenty-five thousand, nine hundred nine".