225431221 has 2 divisors, whose sum is σ = 225431222. Its totient is φ = 225431220.

The previous prime is 225431209. The next prime is 225431231. The reversal of 225431221 is 122134522.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 225420196 + 11025 = 15014^2 + 105^2 .

It is a cyclic number.

It is not a de Polignac number, because 225431221 - 2⁷ = 225431093 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 225431192 and 225431201.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (225431231) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 112715610 + 112715611.

It is an arithmetic number, because the mean of its divisors is an integer number (112715611).

Almost surely, 2^225431221 is an apocalyptic number.

It is an amenable number.

225431221 is a deficient number, since it is larger than the sum of its proper divisors (1).

225431221 is an equidigital number, since it uses as much as digits as its factorization.

225431221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 960, while the sum is 22.

The square root of 225431221 is about 15014.3671528307. The cubic root of 225431221 is about 608.6085105885.

Adding to 225431221 its reverse (122134522), we get a palindrome (347565743).

The spelling of 225431221 in words is "two hundred twenty-five million, four hundred thirty-one thousand, two hundred twenty-one".