225198121 has 2 divisors, whose sum is σ = 225198122. Its totient is φ = 225198120.

The previous prime is 225198119. The next prime is 225198157. The reversal of 225198121 is 121891522.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 144000000 + 81198121 = 12000^2 + 9011^2 .

It is a cyclic number.

It is not a de Polignac number, because 225198121 - 2¹ = 225198119 is a prime.

Together with 225198119, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (225198161) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 112599060 + 112599061.

It is an arithmetic number, because the mean of its divisors is an integer number (112599061).

Almost surely, 2^225198121 is an apocalyptic number.

It is an amenable number.

225198121 is a deficient number, since it is larger than the sum of its proper divisors (1).

225198121 is an equidigital number, since it uses as much as digits as its factorization.

225198121 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2880, while the sum is 31.

The square root of 225198121 is about 15006.6025801978. The cubic root of 225198121 is about 608.3986674726.

The spelling of 225198121 in words is "two hundred twenty-five million, one hundred ninety-eight thousand, one hundred twenty-one".