225621 has 24 divisors (see below), whose sum is σ = 370656. Its totient is φ = 131040.

The previous prime is 225619. The next prime is 225629. The reversal of 225621 is 126522.

It is not a de Polignac number, because 225621 - 2¹ = 225619 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 225594 and 225603.

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 225621.

It is not an unprimeable number, because it can be changed into a prime (225629) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4231 + ... + 4283.

It is an arithmetic number, because the mean of its divisors is an integer number (15444).

2²²⁵⁶²¹ is an apocalyptic number.

It is an amenable number.

225621 is a deficient number, since it is larger than the sum of its proper divisors (145035).

225621 is a wasteful number, since it uses less digits than its factorization.

225621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 113 (or 110 counting only the distinct ones).

The product of its digits is 240, while the sum is 18.

The square root of 225621 is about 474.9957894550. The cubic root of 225621 is about 60.8779248131.

Subtracting from 225621 its reverse (126522), we obtain a palindrome (99099).

The spelling of 225621 in words is "two hundred twenty-five thousand, six hundred twenty-one".