225123021 has 12 divisors (see below), whose sum is σ = 329633148. Its totient is φ = 148025664.

The previous prime is 225123013. The next prime is 225123053. The reversal of 225123021 is 120321522.

It can be written as a sum of positive squares in 2 ways, for example, as 112656996 + 112466025 = 10614^2 + 10605^2 .

It is not a de Polignac number, because 225123021 - 2³ = 225123013 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 225122985 and 225123003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (225123071) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 170670 + ... + 171983.

It is an arithmetic number, because the mean of its divisors is an integer number (27469429).

Almost surely, 2^225123021 is an apocalyptic number.

It is an amenable number.

225123021 is a deficient number, since it is larger than the sum of its proper divisors (104510127).

225123021 is a wasteful number, since it uses less digits than its factorization.

225123021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 342732 (or 342729 counting only the distinct ones).

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

The square root of 225123021 is about 15004.1001396285. The cubic root of 225123021 is about 608.3310295194.

Adding to 225123021 its reverse (120321522), we get a palindrome (345444543).

The spelling of 225123021 in words is "two hundred twenty-five million, one hundred twenty-three thousand, twenty-one".