225581621 has 4 divisors (see below), whose sum is σ = 229837932. Its totient is φ = 221325312.

The previous prime is 225581611. The next prime is 225581647. The reversal of 225581621 is 126185522.

225581621 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 110019121 + 115562500 = 10489^2 + 10750^2 .

It is a cyclic number.

It is not a de Polignac number, because 225581621 - 2¹⁴ = 225565237 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (225581611) 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, 2128076 + ... + 2128181.

It is an arithmetic number, because the mean of its divisors is an integer number (57459483).

Almost surely, 2^225581621 is an apocalyptic number.

It is an amenable number.

225581621 is a deficient number, since it is larger than the sum of its proper divisors (4256311).

225581621 is an equidigital number, since it uses as much as digits as its factorization.

225581621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4256310.

The product of its digits is 9600, while the sum is 32.

The square root of 225581621 is about 15019.3748538346. The cubic root of 225581621 is about 608.7438280937.

The spelling of 225581621 in words is "two hundred twenty-five million, five hundred eighty-one thousand, six hundred twenty-one".