225507661 has 2 divisors, whose sum is σ = 225507662. Its totient is φ = 225507660.

The previous prime is 225507643. The next prime is 225507691. The reversal of 225507661 is 166705522.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 219602761 + 5904900 = 14819^2 + 2430^2 .

It is a cyclic number.

It is not a de Polignac number, because 225507661 - 2⁵ = 225507629 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (225507631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 112753830 + 112753831.

It is an arithmetic number, because the mean of its divisors is an integer number (112753831).

Almost surely, 2^225507661 is an apocalyptic number.

It is an amenable number.

225507661 is a deficient number, since it is larger than the sum of its proper divisors (1).

225507661 is an equidigital number, since it uses as much as digits as its factorization.

225507661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 25200, while the sum is 34.

The square root of 225507661 is about 15016.9124989127. The cubic root of 225507661 is about 608.6772925095.

The spelling of 225507661 in words is "two hundred twenty-five million, five hundred seven thousand, six hundred sixty-one".