225921 has 4 divisors (see below), whose sum is σ = 301232. Its totient is φ = 150612.

The previous prime is 225919. The next prime is 225931. The reversal of 225921 is 129522.

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.

It is not a de Polignac number, because 225921 - 2¹ = 225919 is a prime.

It is a D-number.

It is a Duffinian number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 225921.

It is not an unprimeable number, because it can be changed into a prime (225931) 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, 37651 + ... + 37656.

It is an arithmetic number, because the mean of its divisors is an integer number (75308).

2²²⁵⁹²¹ is an apocalyptic number.

It is an amenable number.

225921 is a deficient number, since it is larger than the sum of its proper divisors (75311).

225921 is an equidigital number, since it uses as much as digits as its factorization.

225921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 75310.

The product of its digits is 360, while the sum is 21.

The square root of 225921 is about 475.3114768234. The cubic root of 225921 is about 60.9048952469.

The spelling of 225921 in words is "two hundred twenty-five thousand, nine hundred twenty-one".