225731521 has 2 divisors, whose sum is σ = 225731522. Its totient is φ = 225731520.

The previous prime is 225731503. The next prime is 225731543. The reversal of 225731521 is 125137522.

225731521 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 209207296 + 16524225 = 14464^2 + 4065^2 .

It is a cyclic number.

It is not a de Polignac number, because 225731521 - 2⁵ = 225731489 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 225731521.

It is not a weakly prime, because it can be changed into another prime (225731921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 112865760 + 112865761.

It is an arithmetic number, because the mean of its divisors is an integer number (112865761).

Almost surely, 2^225731521 is an apocalyptic number.

It is an amenable number.

225731521 is a deficient number, since it is larger than the sum of its proper divisors (1).

225731521 is an equidigital number, since it uses as much as digits as its factorization.

225731521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4200, while the sum is 28.

The square root of 225731521 is about 15024.3642461170. The cubic root of 225731521 is about 608.8786359070.

The spelling of 225731521 in words is "two hundred twenty-five million, seven hundred thirty-one thousand, five hundred twenty-one".