225372221 has 4 divisors (see below), whose sum is σ = 225707772. Its totient is φ = 225036672.

The previous prime is 225372211. The next prime is 225372223. The reversal of 225372221 is 122273522.

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 144120025 + 81252196 = 12005^2 + 9014^2 .

It is a cyclic number.

It is not a de Polignac number, because 225372221 - 2¹⁰ = 225371197 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 (225372223) 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 in 3 ways as a sum of consecutive naturals, for example, 166766 + ... + 168111.

It is an arithmetic number, because the mean of its divisors is an integer number (56426943).

Almost surely, 2^225372221 is an apocalyptic number.

It is an amenable number.

225372221 is a deficient number, since it is larger than the sum of its proper divisors (335551).

225372221 is an equidigital number, since it uses as much as digits as its factorization.

225372221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 335550.

The product of its digits is 3360, while the sum is 26.

The square root of 225372221 is about 15012.4022394819. The cubic root of 225372221 is about 608.5554108226. Note that the first 3 decimals are identical.

The spelling of 225372221 in words is "two hundred twenty-five million, three hundred seventy-two thousand, two hundred twenty-one".