225015221 has 2 divisors, whose sum is σ = 225015222. Its totient is φ = 225015220.

The previous prime is 225015209. The next prime is 225015277. The reversal of 225015221 is 122510522.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 209844196 + 15171025 = 14486^2 + 3895^2 .

It is a cyclic number.

It is not a de Polignac number, because 225015221 - 2¹⁰ = 225014197 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 225015193 and 225015202.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (225015121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 112507610 + 112507611.

It is an arithmetic number, because the mean of its divisors is an integer number (112507611).

Almost surely, 2^225015221 is an apocalyptic number.

It is an amenable number.

225015221 is a deficient number, since it is larger than the sum of its proper divisors (1).

225015221 is an equidigital number, since it uses as much as digits as its factorization.

225015221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 400, while the sum is 20.

The square root of 225015221 is about 15000.5073580863. The cubic root of 225015221 is about 608.2339143883.

Adding to 225015221 its reverse (122510522), we get a palindrome (347525743).

It can be divided in two parts, 2250 and 15221, that added together give a palindrome (17471).

The spelling of 225015221 in words is "two hundred twenty-five million, fifteen thousand, two hundred twenty-one".